xref: /aosp_15_r20/external/selinux/libsepol/include/sepol/policydb/avtab.h (revision 2d543d20722ada2425b5bdab9d0d1d29470e7bba)
1 
2 /* Author : Stephen Smalley, <[email protected]> */
3 
4 /*
5  * Updated: Yuichi Nakamura <[email protected]>
6  * 	Tuned number of hash slots for avtab to reduce memory usage
7  */
8 
9 /* Updated: Frank Mayer <[email protected]> and Karl MacMillan <[email protected]>
10  *
11  * 	Added conditional policy language extensions
12  *
13  * Copyright (C) 2003 Tresys Technology, LLC
14  *
15  *  This library is free software; you can redistribute it and/or
16  *  modify it under the terms of the GNU Lesser General Public
17  *  License as published by the Free Software Foundation; either
18  *  version 2.1 of the License, or (at your option) any later version.
19  *
20  *  This library is distributed in the hope that it will be useful,
21  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
23  *  Lesser General Public License for more details.
24  *
25  *  You should have received a copy of the GNU Lesser General Public
26  *  License along with this library; if not, write to the Free Software
27  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
28  */
29 
30 /* FLASK */
31 
32 /*
33  * An access vector table (avtab) is a hash table
34  * of access vectors and transition types indexed
35  * by a type pair and a class.  An access vector
36  * table is used to represent the type enforcement
37  * tables.
38  */
39 
40 #ifndef _SEPOL_POLICYDB_AVTAB_H_
41 #define _SEPOL_POLICYDB_AVTAB_H_
42 
43 #include <sys/types.h>
44 #include <stdint.h>
45 
46 #ifdef __cplusplus
47 extern "C" {
48 #endif
49 
50 typedef struct avtab_key {
51 	uint16_t source_type;
52 	uint16_t target_type;
53 	uint16_t target_class;
54 #define AVTAB_ALLOWED		0x0001
55 #define AVTAB_AUDITALLOW	0x0002
56 #define AVTAB_AUDITDENY		0x0004
57 #define AVTAB_NEVERALLOW	0x0080
58 #define AVTAB_AV		(AVTAB_ALLOWED | AVTAB_AUDITALLOW | AVTAB_AUDITDENY)
59 #define AVTAB_TRANSITION	0x0010
60 #define AVTAB_MEMBER		0x0020
61 #define AVTAB_CHANGE		0x0040
62 #define AVTAB_TYPE		(AVTAB_TRANSITION | AVTAB_MEMBER | AVTAB_CHANGE)
63 #define AVTAB_XPERMS_ALLOWED	0x0100
64 #define AVTAB_XPERMS_AUDITALLOW	0x0200
65 #define AVTAB_XPERMS_DONTAUDIT	0x0400
66 #define AVTAB_XPERMS_NEVERALLOW	0x0800
67 #define AVTAB_XPERMS		(AVTAB_XPERMS_ALLOWED | AVTAB_XPERMS_AUDITALLOW | AVTAB_XPERMS_DONTAUDIT)
68 #define AVTAB_ENABLED_OLD	0x80000000
69 #define AVTAB_ENABLED		0x8000	/* reserved for used in cond_avtab */
70 	uint16_t specified;	/* what fields are specified */
71 } avtab_key_t;
72 
73 typedef struct avtab_extended_perms {
74 
75 #define AVTAB_XPERMS_IOCTLFUNCTION	0x01
76 #define AVTAB_XPERMS_IOCTLDRIVER	0x02
77 #define AVTAB_XPERMS_NLMSG	0x03
78 	/* extension of the avtab_key specified */
79 	uint8_t specified;
80 	uint8_t driver;
81 	uint32_t perms[8];
82 } avtab_extended_perms_t;
83 
84 typedef struct avtab_datum {
85 	uint32_t data;		/* access vector or type */
86 	avtab_extended_perms_t *xperms;
87 } avtab_datum_t;
88 
89 typedef struct avtab_node *avtab_ptr_t;
90 
91 struct avtab_node {
92 	avtab_key_t key;
93 	avtab_datum_t datum;
94 	avtab_ptr_t next;
95 	void *parse_context;	/* generic context pointer used by parser;
96 				 * not saved in binary policy */
97 	unsigned merged;	/* flag for avtab_write only;
98 				   not saved in binary policy */
99 };
100 
101 typedef struct avtab {
102 	avtab_ptr_t *htable;
103 	uint32_t nel;		/* number of elements */
104 	uint32_t nslot;         /* number of hash slots */
105 	uint32_t mask;          /* mask to compute hash func */
106 } avtab_t;
107 
108 extern int avtab_init(avtab_t *);
109 extern int avtab_alloc(avtab_t *, uint32_t);
110 extern int avtab_insert(avtab_t * h, avtab_key_t * k, avtab_datum_t * d);
111 
112 extern avtab_datum_t *avtab_search(avtab_t * h, avtab_key_t * k);
113 
114 extern void avtab_destroy(avtab_t * h);
115 
116 extern int avtab_map(const avtab_t * h,
117 		     int (*apply) (avtab_key_t * k,
118 				   avtab_datum_t * d, void *args), void *args);
119 
120 extern void avtab_hash_eval(avtab_t * h, char *tag);
121 
122 struct policy_file;
123 extern int avtab_read_item(struct policy_file *fp, uint32_t vers, avtab_t * a,
124 			   int (*insert) (avtab_t * a, avtab_key_t * k,
125 					  avtab_datum_t * d, void *p), void *p);
126 
127 extern int avtab_read(avtab_t * a, struct policy_file *fp, uint32_t vers);
128 
129 extern avtab_ptr_t avtab_insert_nonunique(avtab_t * h, avtab_key_t * key,
130 					  avtab_datum_t * datum);
131 
132 extern avtab_ptr_t avtab_insert_with_parse_context(avtab_t * h,
133 						   avtab_key_t * key,
134 						   avtab_datum_t * datum,
135 						   void *parse_context);
136 
137 extern avtab_ptr_t avtab_search_node(avtab_t * h, avtab_key_t * key);
138 
139 extern avtab_ptr_t avtab_search_node_next(avtab_ptr_t node, int specified);
140 
141 #define MAX_AVTAB_HASH_BITS 20
142 #define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS)
143 #define MAX_AVTAB_HASH_MASK (MAX_AVTAB_HASH_BUCKETS-1)
144 /* avtab_alloc uses one bucket per 2-4 elements, so adjust to get maximum buckets */
145 #define MAX_AVTAB_SIZE (MAX_AVTAB_HASH_BUCKETS << 1)
146 
147 #ifdef __cplusplus
148 }
149 #endif
150 
151 #endif				/* _AVTAB_H_ */
152 
153 /* FLASK */
154