1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * An access vector table (avtab) is a hash table
4 * of access vectors and transition types indexed
5 * by a type pair and a class. An access vector
6 * table is used to represent the type enforcement
7 * tables.
8 *
9 * Author : Stephen Smalley, <[email protected]>
10 */
11
12 /* Updated: Frank Mayer <[email protected]> and
13 * Karl MacMillan <[email protected]>
14 * Added conditional policy language extensions
15 * Copyright (C) 2003 Tresys Technology, LLC
16 *
17 * Updated: Yuichi Nakamura <[email protected]>
18 * Tuned number of hash slots for avtab to reduce memory usage
19 */
20
21 #ifndef _SS_AVTAB_H_
22 #define _SS_AVTAB_H_
23
24 #include "security.h"
25
26 struct avtab_key {
27 u16 source_type; /* source type */
28 u16 target_type; /* target type */
29 u16 target_class; /* target object class */
30 #define AVTAB_ALLOWED 0x0001
31 #define AVTAB_AUDITALLOW 0x0002
32 #define AVTAB_AUDITDENY 0x0004
33 #define AVTAB_AV (AVTAB_ALLOWED | AVTAB_AUDITALLOW | AVTAB_AUDITDENY)
34 #define AVTAB_TRANSITION 0x0010
35 #define AVTAB_MEMBER 0x0020
36 #define AVTAB_CHANGE 0x0040
37 #define AVTAB_TYPE (AVTAB_TRANSITION | AVTAB_MEMBER | AVTAB_CHANGE)
38 /* extended permissions */
39 #define AVTAB_XPERMS_ALLOWED 0x0100
40 #define AVTAB_XPERMS_AUDITALLOW 0x0200
41 #define AVTAB_XPERMS_DONTAUDIT 0x0400
42 #define AVTAB_XPERMS \
43 (AVTAB_XPERMS_ALLOWED | AVTAB_XPERMS_AUDITALLOW | \
44 AVTAB_XPERMS_DONTAUDIT)
45 #define AVTAB_ENABLED_OLD 0x80000000 /* reserved for used in cond_avtab */
46 #define AVTAB_ENABLED 0x8000 /* reserved for used in cond_avtab */
47 u16 specified; /* what field is specified */
48 };
49
50 /*
51 * For operations that require more than the 32 permissions provided by the avc
52 * extended permissions may be used to provide 256 bits of permissions.
53 */
54 struct avtab_extended_perms {
55 /* These are not flags. All 256 values may be used */
56 #define AVTAB_XPERMS_IOCTLFUNCTION 0x01
57 #define AVTAB_XPERMS_IOCTLDRIVER 0x02
58 #define AVTAB_XPERMS_NLMSG 0x03
59 /* extension of the avtab_key specified */
60 u8 specified; /* ioctl, netfilter, ... */
61 /*
62 * if 256 bits is not adequate as is often the case with ioctls, then
63 * multiple extended perms may be used and the driver field
64 * specifies which permissions are included.
65 */
66 u8 driver;
67 /* 256 bits of permissions */
68 struct extended_perms_data perms;
69 };
70
71 struct avtab_datum {
72 union {
73 u32 data; /* access vector or type value */
74 struct avtab_extended_perms *xperms;
75 } u;
76 };
77
78 struct avtab_node {
79 struct avtab_key key;
80 struct avtab_datum datum;
81 struct avtab_node *next;
82 };
83
84 struct avtab {
85 struct avtab_node **htable;
86 u32 nel; /* number of elements */
87 u32 nslot; /* number of hash slots */
88 u32 mask; /* mask to compute hash func */
89 };
90
91 void avtab_init(struct avtab *h);
92 int avtab_alloc(struct avtab *h, u32 nrules);
93 int avtab_alloc_dup(struct avtab *new, const struct avtab *orig);
94 void avtab_destroy(struct avtab *h);
95
96 #define MAX_AVTAB_HASH_BITS 16
97 #define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS)
98
99 #ifdef CONFIG_SECURITY_SELINUX_DEBUG
100 void avtab_hash_eval(struct avtab *h, const char *tag);
101 #else
avtab_hash_eval(struct avtab * h,const char * tag)102 static inline void avtab_hash_eval(struct avtab *h, const char *tag)
103 {
104 }
105 #endif
106
107 struct policydb;
108 struct policy_file;
109 int avtab_read_item(struct avtab *a, struct policy_file *fp, struct policydb *pol,
110 int (*insert)(struct avtab *a, const struct avtab_key *k,
111 const struct avtab_datum *d, void *p),
112 void *p, bool conditional);
113
114 int avtab_read(struct avtab *a, struct policy_file *fp, struct policydb *pol);
115 int avtab_write_item(struct policydb *p, const struct avtab_node *cur,
116 struct policy_file *fp);
117 int avtab_write(struct policydb *p, struct avtab *a, struct policy_file *fp);
118
119 struct avtab_node *avtab_insert_nonunique(struct avtab *h,
120 const struct avtab_key *key,
121 const struct avtab_datum *datum);
122
123 struct avtab_node *avtab_search_node(struct avtab *h,
124 const struct avtab_key *key);
125 struct avtab_node *avtab_search_node_next(struct avtab_node *node,
126 u16 specified);
127
128 #endif /* _SS_AVTAB_H_ */
129