1 /*
2  * An access vector table (avtab) is a hash table
3  * of access vectors and transition types indexed
4  * by a type pair and a class.  An access vector
5  * table is used to represent the type enforcement
6  * tables.
7  *
8  *  Author : Stephen Smalley, <sds@epoch.ncsc.mil>
9  */
10 
11 /* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
12  *
13  *     Added conditional policy language extensions
14  *
15  * Copyright (C) 2003 Tresys Technology, LLC
16  *    This program is free software; you can redistribute it and/or modify
17  *      it under the terms of the GNU General Public License as published by
18  *    the Free Software Foundation, version 2.
19  *
20  * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp>
21  * 	Tuned number of hash slots for avtab to reduce memory usage
22  */
23 
24 /* Ported to Xen 3.0, George Coker, <gscoker@alpha.ncsc.mil> */
25 
26 #ifndef _SS_AVTAB_H_
27 #define _SS_AVTAB_H_
28 
29 struct avtab_key {
30     u16 source_type;    /* source type */
31     u16 target_type;    /* target type */
32     u16 target_class;    /* target object class */
33 #define AVTAB_ALLOWED     1
34 #define AVTAB_AUDITALLOW  2
35 #define AVTAB_AUDITDENY   4
36 #define AVTAB_AV         (AVTAB_ALLOWED | AVTAB_AUDITALLOW | AVTAB_AUDITDENY)
37 #define AVTAB_TRANSITION 16
38 #define AVTAB_MEMBER     32
39 #define AVTAB_CHANGE     64
40 #define AVTAB_TYPE       (AVTAB_TRANSITION | AVTAB_MEMBER | AVTAB_CHANGE)
41 #define AVTAB_ENABLED_OLD    0x80000000 /* reserved for used in cond_avtab */
42 #define AVTAB_ENABLED    0x8000 /* reserved for used in cond_avtab */
43     u16 specified;    /* what field is specified */
44 };
45 
46 struct avtab_datum {
47     u32 data; /* access vector or type value */
48 };
49 
50 struct avtab_node {
51     struct avtab_key key;
52     struct avtab_datum datum;
53     struct avtab_node *next;
54 };
55 
56 struct avtab {
57     struct avtab_node **htable;
58     u32 nel;    /* number of elements */
59     u32 nslot;      /* number of hash slots */
60     u16 mask;       /* mask to compute hash func */
61 };
62 
63 int avtab_init(struct avtab *);
64 int avtab_alloc(struct avtab *, u32);
65 struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *k);
66 void avtab_destroy(struct avtab *h);
67 void avtab_hash_eval(struct avtab *h, char *tag);
68 
69 struct policydb;
70 int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
71             int (*insert)(struct avtab *a, struct avtab_key *k,
72                   struct avtab_datum *d, void *p),
73             void *p);
74 
75 int avtab_read(struct avtab *a, void *fp, struct policydb *pol);
76 
77 struct avtab_node *avtab_insert_nonunique(struct avtab *h,
78                             struct avtab_key *key, struct avtab_datum *datum);
79 
80 struct avtab_node *avtab_search_node(struct avtab *h, struct avtab_key *key);
81 
82 struct avtab_node *avtab_search_node_next(struct avtab_node *node,
83                                                                 int specified);
84 
85 #define MAX_AVTAB_HASH_BITS 13
86 #define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS)
87 #define MAX_AVTAB_HASH_MASK (MAX_AVTAB_HASH_BUCKETS-1)
88 #define MAX_AVTAB_SIZE MAX_AVTAB_HASH_BUCKETS
89 
90 #endif    /* _SS_AVTAB_H_ */
91 
92