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, <sds@tycho.nsa.gov>
10  */
11 
12 /* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
13  *
14  * 	Added conditional policy language extensions
15  *
16  * Copyright (C) 2003 Tresys Technology, LLC
17  *
18  * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp>
19  * 	Tuned number of hash slots for avtab to reduce memory usage
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		(AVTAB_XPERMS_ALLOWED | \
43 				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 	/* extension of the avtab_key specified */
59 	u8 specified; /* ioctl, netfilter, ... */
60 	/*
61 	 * if 256 bits is not adequate as is often the case with ioctls, then
62 	 * multiple extended perms may be used and the driver field
63 	 * specifies which permissions are included.
64 	 */
65 	u8 driver;
66 	/* 256 bits of permissions */
67 	struct extended_perms_data perms;
68 };
69 
70 struct avtab_datum {
71 	union {
72 		u32 data; /* access vector or type value */
73 		struct avtab_extended_perms *xperms;
74 	} u;
75 };
76 
77 struct avtab_node {
78 	struct avtab_key key;
79 	struct avtab_datum datum;
80 	struct avtab_node *next;
81 };
82 
83 struct avtab {
84 	struct avtab_node **htable;
85 	u32 nel;	/* number of elements */
86 	u32 nslot;      /* number of hash slots */
87 	u32 mask;       /* mask to compute hash func */
88 };
89 
90 void avtab_init(struct avtab *h);
91 int avtab_alloc(struct avtab *, u32);
92 int avtab_alloc_dup(struct avtab *new, const struct avtab *orig);
93 struct avtab_datum *avtab_search(struct avtab *h, const struct avtab_key *k);
94 void avtab_destroy(struct avtab *h);
95 void avtab_hash_eval(struct avtab *h, char *tag);
96 
97 struct policydb;
98 int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
99 		    int (*insert)(struct avtab *a, const struct avtab_key *k,
100 				  const struct avtab_datum *d, void *p),
101 		    void *p);
102 
103 int avtab_read(struct avtab *a, void *fp, struct policydb *pol);
104 int avtab_write_item(struct policydb *p, const struct avtab_node *cur, void *fp);
105 int avtab_write(struct policydb *p, struct avtab *a, void *fp);
106 
107 struct avtab_node *avtab_insert_nonunique(struct avtab *h,
108 					  const struct avtab_key *key,
109 					  const struct avtab_datum *datum);
110 
111 struct avtab_node *avtab_search_node(struct avtab *h,
112 				     const struct avtab_key *key);
113 
114 struct avtab_node *avtab_search_node_next(struct avtab_node *node, int specified);
115 
116 #define MAX_AVTAB_HASH_BITS 16
117 #define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS)
118 
119 #endif	/* _SS_AVTAB_H_ */
120 
121