1 /* Authors: Karl MacMillan <kmacmillan@tresys.com> 2 * Frank Mayer <mayerf@tresys.com> 3 * 4 * Copyright (C) 2003 - 2005 Tresys Technology, LLC 5 * 6 * This library is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * This library is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with this library; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21 #ifndef _SEPOL_POLICYDB_CONDITIONAL_H_ 22 #define _SEPOL_POLICYDB_CONDITIONAL_H_ 23 24 #include <sepol/policydb/flask_types.h> 25 #include <sepol/policydb/avtab.h> 26 #include <sepol/policydb/symtab.h> 27 #include <sepol/policydb/policydb.h> 28 29 #define COND_EXPR_MAXDEPTH 10 30 31 /* this is the max unique bools in a conditional expression 32 * for which we precompute all outcomes for the expression. 33 * 34 * NOTE - do _NOT_ use value greater than 5 because 35 * cond_node_t->expr_pre_comp can only hold at most 32 values 36 */ 37 #define COND_MAX_BOOLS 5 38 39 /* 40 * A conditional expression is a list of operators and operands 41 * in reverse polish notation. 42 */ 43 typedef struct cond_expr { 44 #define COND_BOOL 1 /* plain bool */ 45 #define COND_NOT 2 /* !bool */ 46 #define COND_OR 3 /* bool || bool */ 47 #define COND_AND 4 /* bool && bool */ 48 #define COND_XOR 5 /* bool ^ bool */ 49 #define COND_EQ 6 /* bool == bool */ 50 #define COND_NEQ 7 /* bool != bool */ 51 #define COND_LAST COND_NEQ 52 uint32_t expr_type; 53 uint32_t bool; 54 struct cond_expr *next; 55 } cond_expr_t; 56 57 /* 58 * Each cond_node_t contains a list of rules to be enabled/disabled 59 * depending on the current value of the conditional expression. This 60 * struct is for that list. 61 */ 62 typedef struct cond_av_list { 63 avtab_ptr_t node; 64 struct cond_av_list *next; 65 } cond_av_list_t; 66 67 /* 68 * A cond node represents a conditional block in a policy. It 69 * contains a conditional expression, the current state of the expression, 70 * two lists of rules to enable/disable depending on the value of the 71 * expression (the true list corresponds to if and the false list corresponds 72 * to else).. 73 */ 74 typedef struct cond_node { 75 int cur_state; 76 cond_expr_t *expr; 77 /* these true/false lists point into te_avtab when that is used */ 78 cond_av_list_t *true_list; 79 cond_av_list_t *false_list; 80 /* and these are used during parsing and for modules */ 81 avrule_t *avtrue_list; 82 avrule_t *avfalse_list; 83 /* these fields are not written to binary policy */ 84 unsigned int nbools; 85 uint32_t bool_ids[COND_MAX_BOOLS]; 86 uint32_t expr_pre_comp; 87 struct cond_node *next; 88 /* a tunable conditional, calculated and used at expansion */ 89 #define COND_NODE_FLAGS_TUNABLE 0x01 90 uint32_t flags; 91 } cond_node_t; 92 93 extern int cond_evaluate_expr(policydb_t * p, cond_expr_t * expr); 94 extern cond_expr_t *cond_copy_expr(cond_expr_t * expr); 95 96 extern int cond_expr_equal(cond_node_t * a, cond_node_t * b); 97 extern int cond_normalize_expr(policydb_t * p, cond_node_t * cn); 98 extern void cond_node_destroy(cond_node_t * node); 99 extern void cond_expr_destroy(cond_expr_t * expr); 100 101 extern cond_node_t *cond_node_find(policydb_t * p, 102 cond_node_t * needle, cond_node_t * haystack, 103 int *was_created); 104 105 extern cond_node_t *cond_node_create(policydb_t * p, cond_node_t * node); 106 107 extern cond_node_t *cond_node_search(policydb_t * p, cond_node_t * list, 108 cond_node_t * cn); 109 110 extern int evaluate_conds(policydb_t * p); 111 112 extern avtab_datum_t *cond_av_list_search(avtab_key_t * key, 113 cond_av_list_t * cond_list); 114 115 extern void cond_av_list_destroy(cond_av_list_t * list); 116 117 extern void cond_optimize_lists(cond_list_t * cl); 118 119 extern int cond_policydb_init(policydb_t * p); 120 extern void cond_policydb_destroy(policydb_t * p); 121 extern void cond_list_destroy(cond_list_t * list); 122 123 extern int cond_init_bool_indexes(policydb_t * p); 124 extern int cond_destroy_bool(hashtab_key_t key, hashtab_datum_t datum, void *p); 125 126 extern int cond_index_bool(hashtab_key_t key, hashtab_datum_t datum, 127 void *datap); 128 129 extern int cond_read_bool(policydb_t * p, hashtab_t h, struct policy_file *fp); 130 131 extern int cond_read_list(policydb_t * p, cond_list_t ** list, void *fp); 132 133 extern void cond_compute_av(avtab_t * ctab, avtab_key_t * key, 134 struct sepol_av_decision *avd); 135 136 #endif /* _CONDITIONAL_H_ */ 137