LXR linux/security/selinux/ss/conditional.h

   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,
  77                struct av_decision *avd, struct extended_perms *xperms);
  78void cond_compute_xperms(struct avtab *ctab, struct avtab_key *key,
  79                struct extended_perms_decision *xpermd);
  80int evaluate_cond_node(struct policydb *p, struct cond_node *node);
  81
  82#endif /* _CONDITIONAL_H_ */
  83