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
26struct 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 */
54struct 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
70struct avtab_datum {
71	union {
72		u32 data; /* access vector or type value */
73		struct avtab_extended_perms *xperms;
74	} u;
75};
76
77struct avtab_node {
78	struct avtab_key key;
79	struct avtab_datum datum;
80	struct avtab_node *next;
81};
82
83struct 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
90void avtab_init(struct avtab *h);
91int avtab_alloc(struct avtab *, u32);
92int avtab_alloc_dup(struct avtab *new, const struct avtab *orig);
93struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *k);
94void avtab_destroy(struct avtab *h);
95void avtab_hash_eval(struct avtab *h, char *tag);
96
97struct policydb;
98int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
99		    int (*insert)(struct avtab *a, struct avtab_key *k,
100				  struct avtab_datum *d, void *p),
101		    void *p);
102
103int avtab_read(struct avtab *a, void *fp, struct policydb *pol);
104int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp);
105int avtab_write(struct policydb *p, struct avtab *a, void *fp);
106
107struct avtab_node *avtab_insert_nonunique(struct avtab *h, struct avtab_key *key,
108					  struct avtab_datum *datum);
109
110struct avtab_node *avtab_search_node(struct avtab *h, struct avtab_key *key);
111
112struct avtab_node *avtab_search_node_next(struct avtab_node *node, int specified);
113
114#define MAX_AVTAB_HASH_BITS 16
115#define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS)
116
117#endif	/* _SS_AVTAB_H_ */
118
119