Joshua Brindle | 13cd4c8 | 2008-08-19 15:30:36 -0400 | [diff] [blame^] | 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 8 |
| 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 using 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 | /* */ |
| 88 | struct cond_node *next; |
| 89 | } cond_node_t; |
| 90 | |
| 91 | extern int cond_evaluate_expr(policydb_t * p, cond_expr_t * expr); |
| 92 | extern cond_expr_t *cond_copy_expr(cond_expr_t * expr); |
| 93 | |
| 94 | extern int cond_expr_equal(cond_node_t * a, cond_node_t * b); |
| 95 | extern int cond_normalize_expr(policydb_t * p, cond_node_t * cn); |
| 96 | extern void cond_node_destroy(cond_node_t * node); |
| 97 | extern void cond_expr_destroy(cond_expr_t * expr); |
| 98 | |
| 99 | extern cond_node_t *cond_node_find(policydb_t * p, |
| 100 | cond_node_t * needle, cond_node_t * haystack, |
| 101 | int *was_created); |
| 102 | |
| 103 | extern cond_node_t *cond_node_create(policydb_t * p, cond_node_t * node); |
| 104 | |
| 105 | extern cond_node_t *cond_node_search(policydb_t * p, cond_node_t * list, |
| 106 | cond_node_t * cn); |
| 107 | |
| 108 | extern int evaluate_conds(policydb_t * p); |
| 109 | |
| 110 | extern avtab_datum_t *cond_av_list_search(avtab_key_t * key, |
| 111 | cond_av_list_t * cond_list); |
| 112 | |
| 113 | extern void cond_av_list_destroy(cond_av_list_t * list); |
| 114 | |
| 115 | extern void cond_optimize_lists(cond_list_t * cl); |
| 116 | |
| 117 | extern int cond_policydb_init(policydb_t * p); |
| 118 | extern void cond_policydb_destroy(policydb_t * p); |
| 119 | extern void cond_list_destroy(cond_list_t * list); |
| 120 | |
| 121 | extern int cond_init_bool_indexes(policydb_t * p); |
| 122 | extern int cond_destroy_bool(hashtab_key_t key, hashtab_datum_t datum, void *p); |
| 123 | |
| 124 | extern int cond_index_bool(hashtab_key_t key, hashtab_datum_t datum, |
| 125 | void *datap); |
| 126 | |
| 127 | extern int cond_read_bool(policydb_t * p, hashtab_t h, struct policy_file *fp); |
| 128 | |
| 129 | extern int cond_read_list(policydb_t * p, cond_list_t ** list, void *fp); |
| 130 | |
| 131 | extern void cond_compute_av(avtab_t * ctab, avtab_key_t * key, |
| 132 | struct sepol_av_decision *avd); |
| 133 | |
| 134 | #endif /* _CONDITIONAL_H_ */ |