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  */
  24 struct 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  */
  43 struct 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  */
  55 struct 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
  63 int cond_policydb_init(struct policydb *p);
  64 void cond_policydb_destroy(struct policydb *p);
  65
  66 int cond_init_bool_indexes(struct policydb *p);
  67 int cond_destroy_bool(void *key, void *datum, void *p);
  68
  69 int cond_index_bool(void *key, void *datum, void *datap);
  70
  71 int cond_read_bool(struct policydb *p, struct hashtab *h, void *fp);
  72 int cond_read_list(struct policydb *p, void *fp);
  73 int cond_write_bool(void *key, void *datum, void *ptr);
  74 int cond_write_list(struct policydb *p, struct cond_node *list, void *fp);
  75
  76 void cond_compute_av(struct avtab *ctab, struct avtab_key *key, struct av_decision *avd);
  77
  78 int evaluate_cond_node(struct policydb *p, struct cond_node *node);
  79
  80 #endif /* _CONDITIONAL_H_ */