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 #ifdef __cplusplus 30 extern "C" { 31 #endif 32 33 #define COND_EXPR_MAXDEPTH 10 34 35 /* this is the max unique bools in a conditional expression 36 * for which we precompute all outcomes for the expression. 37 * 38 * NOTE - do _NOT_ use value greater than 5 because 39 * cond_node_t->expr_pre_comp can only hold at most 32 values 40 */ 41 #define COND_MAX_BOOLS 5 42 43 /* 44 * A conditional expression is a list of operators and operands 45 * in reverse polish notation. 46 */ 47 typedef struct cond_expr { 48 #define COND_BOOL 1 /* plain bool */ 49 #define COND_NOT 2 /* !bool */ 50 #define COND_OR 3 /* bool || bool */ 51 #define COND_AND 4 /* bool && bool */ 52 #define COND_XOR 5 /* bool ^ bool */ 53 #define COND_EQ 6 /* bool == bool */ 54 #define COND_NEQ 7 /* bool != bool */ 55 #define COND_LAST COND_NEQ 56 uint32_t expr_type; 57 uint32_t bool; 58 struct cond_expr *next; 59 } cond_expr_t; 60 61 /* 62 * Each cond_node_t contains a list of rules to be enabled/disabled 63 * depending on the current value of the conditional expression. This 64 * struct is for that list. 65 */ 66 typedef struct cond_av_list { 67 avtab_ptr_t node; 68 struct cond_av_list *next; 69 } cond_av_list_t; 70 71 /* 72 * A cond node represents a conditional block in a policy. It 73 * contains a conditional expression, the current state of the expression, 74 * two lists of rules to enable/disable depending on the value of the 75 * expression (the true list corresponds to if and the false list corresponds 76 * to else).. 77 */ 78 typedef struct cond_node { 79 int cur_state; 80 cond_expr_t *expr; 81 /* these true/false lists point into te_avtab when that is used */ 82 cond_av_list_t *true_list; 83 cond_av_list_t *false_list; 84 /* and these are used during parsing and for modules */ 85 avrule_t *avtrue_list; 86 avrule_t *avfalse_list; 87 /* these fields are not written to binary policy */ 88 unsigned int nbools; 89 uint32_t bool_ids[COND_MAX_BOOLS]; 90 uint32_t expr_pre_comp; 91 struct cond_node *next; 92 /* a tunable conditional, calculated and used at expansion */ 93 #define COND_NODE_FLAGS_TUNABLE 0x01 94 uint32_t flags; 95 } cond_node_t; 96 97 extern int cond_evaluate_expr(policydb_t * p, cond_expr_t * expr); 98 extern cond_expr_t *cond_copy_expr(cond_expr_t * expr); 99 100 extern int cond_expr_equal(cond_node_t * a, cond_node_t * b); 101 extern int cond_normalize_expr(policydb_t * p, cond_node_t * cn); 102 extern void cond_node_destroy(cond_node_t * node); 103 extern void cond_expr_destroy(cond_expr_t * expr); 104 105 extern cond_node_t *cond_node_find(policydb_t * p, 106 cond_node_t * needle, cond_node_t * haystack, 107 int *was_created); 108 109 extern cond_node_t *cond_node_create(policydb_t * p, cond_node_t * node); 110 111 extern cond_node_t *cond_node_search(policydb_t * p, cond_node_t * list, 112 cond_node_t * cn); 113 114 extern int evaluate_conds(policydb_t * p); 115 116 extern avtab_datum_t *cond_av_list_search(avtab_key_t * key, 117 cond_av_list_t * cond_list); 118 119 extern void cond_av_list_destroy(cond_av_list_t * list); 120 121 extern void cond_optimize_lists(cond_list_t * cl); 122 123 extern int cond_policydb_init(policydb_t * p); 124 extern void cond_policydb_destroy(policydb_t * p); 125 extern void cond_list_destroy(cond_list_t * list); 126 127 extern int cond_init_bool_indexes(policydb_t * p); 128 extern int cond_destroy_bool(hashtab_key_t key, hashtab_datum_t datum, void *p); 129 130 extern int cond_index_bool(hashtab_key_t key, hashtab_datum_t datum, 131 void *datap); 132 133 extern int cond_read_bool(policydb_t * p, hashtab_t h, struct policy_file *fp); 134 135 extern int cond_read_list(policydb_t * p, cond_list_t ** list, void *fp); 136 137 extern void cond_compute_av(avtab_t * ctab, avtab_key_t * key, 138 struct sepol_av_decision *avd); 139 140 #ifdef __cplusplus 141 } 142 #endif 143 144 #endif /* _CONDITIONAL_H_ */ 145