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 #include <sys/cdefs.h> 29 30 __BEGIN_DECLS 31 32 #define COND_EXPR_MAXDEPTH 10 33 34 /* this is the max unique bools in a conditional expression 35 * for which we precompute all outcomes for the expression. 36 * 37 * NOTE - do _NOT_ use value greater than 5 because 38 * cond_node_t->expr_pre_comp can only hold at most 32 values 39 */ 40 #define COND_MAX_BOOLS 5 41 42 /* 43 * A conditional expression is a list of operators and operands 44 * in reverse polish notation. 45 */ 46 typedef struct cond_expr { 47 #define COND_BOOL 1 /* plain bool */ 48 #define COND_NOT 2 /* !bool */ 49 #define COND_OR 3 /* bool || bool */ 50 #define COND_AND 4 /* bool && bool */ 51 #define COND_XOR 5 /* bool ^ bool */ 52 #define COND_EQ 6 /* bool == bool */ 53 #define COND_NEQ 7 /* bool != bool */ 54 #define COND_LAST COND_NEQ 55 uint32_t expr_type; 56 uint32_t bool; 57 struct cond_expr *next; 58 } cond_expr_t; 59 60 /* 61 * Each cond_node_t contains a list of rules to be enabled/disabled 62 * depending on the current value of the conditional expression. This 63 * struct is for that list. 64 */ 65 typedef struct cond_av_list { 66 avtab_ptr_t node; 67 struct cond_av_list *next; 68 } cond_av_list_t; 69 70 /* 71 * A cond node represents a conditional block in a policy. It 72 * contains a conditional expression, the current state of the expression, 73 * two lists of rules to enable/disable depending on the value of the 74 * expression (the true list corresponds to if and the false list corresponds 75 * to else).. 76 */ 77 typedef struct cond_node { 78 int cur_state; 79 cond_expr_t *expr; 80 /* these true/false lists point into te_avtab when that is used */ 81 cond_av_list_t *true_list; 82 cond_av_list_t *false_list; 83 /* and these are used during parsing and for modules */ 84 avrule_t *avtrue_list; 85 avrule_t *avfalse_list; 86 /* these fields are not written to binary policy */ 87 unsigned int nbools; 88 uint32_t bool_ids[COND_MAX_BOOLS]; 89 uint32_t expr_pre_comp; 90 struct cond_node *next; 91 /* a tunable conditional, calculated and used at expansion */ 92 #define COND_NODE_FLAGS_TUNABLE 0x01 93 uint32_t flags; 94 } cond_node_t; 95 96 extern int cond_evaluate_expr(policydb_t * p, cond_expr_t * expr); 97 extern cond_expr_t *cond_copy_expr(cond_expr_t * expr); 98 99 extern int cond_expr_equal(cond_node_t * a, cond_node_t * b); 100 extern int cond_normalize_expr(policydb_t * p, cond_node_t * cn); 101 extern void cond_node_destroy(cond_node_t * node); 102 extern void cond_expr_destroy(cond_expr_t * expr); 103 104 extern cond_node_t *cond_node_find(policydb_t * p, 105 cond_node_t * needle, cond_node_t * haystack, 106 int *was_created); 107 108 extern cond_node_t *cond_node_create(policydb_t * p, cond_node_t * node); 109 110 extern cond_node_t *cond_node_search(policydb_t * p, cond_node_t * list, 111 cond_node_t * cn); 112 113 extern int evaluate_conds(policydb_t * p); 114 115 extern avtab_datum_t *cond_av_list_search(avtab_key_t * key, 116 cond_av_list_t * cond_list); 117 118 extern void cond_av_list_destroy(cond_av_list_t * list); 119 120 extern void cond_optimize_lists(cond_list_t * cl); 121 122 extern int cond_policydb_init(policydb_t * p); 123 extern void cond_policydb_destroy(policydb_t * p); 124 extern void cond_list_destroy(cond_list_t * list); 125 126 extern int cond_init_bool_indexes(policydb_t * p); 127 extern int cond_destroy_bool(hashtab_key_t key, hashtab_datum_t datum, void *p); 128 129 extern int cond_index_bool(hashtab_key_t key, hashtab_datum_t datum, 130 void *datap); 131 132 extern int cond_read_bool(policydb_t * p, hashtab_t h, struct policy_file *fp); 133 134 extern int cond_read_list(policydb_t * p, cond_list_t ** list, void *fp); 135 136 extern void cond_compute_av(avtab_t * ctab, avtab_key_t * key, 137 struct sepol_av_decision *avd); 138 139 __END_DECLS 140 #endif /* _CONDITIONAL_H_ */ 141