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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 #ifndef _SS_AVTAB_H_
24 #define _SS_AVTAB_H_
25 
26 #include "security.h"
27 
28 struct avtab_key {
29 	u16 source_type;	/* source type */
30 	u16 target_type;	/* target type */
31 	u16 target_class;	/* target object class */
32 #define AVTAB_ALLOWED		0x0001
33 #define AVTAB_AUDITALLOW	0x0002
34 #define AVTAB_AUDITDENY		0x0004
35 #define AVTAB_AV		(AVTAB_ALLOWED | AVTAB_AUDITALLOW | AVTAB_AUDITDENY)
36 #define AVTAB_TRANSITION	0x0010
37 #define AVTAB_MEMBER		0x0020
38 #define AVTAB_CHANGE		0x0040
39 #define AVTAB_TYPE		(AVTAB_TRANSITION | AVTAB_MEMBER | AVTAB_CHANGE)
40 /* extended permissions */
41 #define AVTAB_XPERMS_ALLOWED	0x0100
42 #define AVTAB_XPERMS_AUDITALLOW	0x0200
43 #define AVTAB_XPERMS_DONTAUDIT	0x0400
44 #define AVTAB_XPERMS		(AVTAB_XPERMS_ALLOWED | \
45 				AVTAB_XPERMS_AUDITALLOW | \
46 				AVTAB_XPERMS_DONTAUDIT)
47 #define AVTAB_ENABLED_OLD   0x80000000 /* reserved for used in cond_avtab */
48 #define AVTAB_ENABLED		0x8000 /* reserved for used in cond_avtab */
49 	u16 specified;	/* what field is specified */
50 };
51 
52 /*
53  * For operations that require more than the 32 permissions provided by the avc
54  * extended permissions may be used to provide 256 bits of permissions.
55  */
56 struct avtab_extended_perms {
57 /* These are not flags. All 256 values may be used */
58 #define AVTAB_XPERMS_IOCTLFUNCTION	0x01
59 #define AVTAB_XPERMS_IOCTLDRIVER	0x02
60 	/* extension of the avtab_key specified */
61 	u8 specified; /* ioctl, netfilter, ... */
62 	/*
63 	 * if 256 bits is not adequate as is often the case with ioctls, then
64 	 * multiple extended perms may be used and the driver field
65 	 * specifies which permissions are included.
66 	 */
67 	u8 driver;
68 	/* 256 bits of permissions */
69 	struct extended_perms_data perms;
70 };
71 
72 struct avtab_datum {
73 	union {
74 		u32 data; /* access vector or type value */
75 		struct avtab_extended_perms *xperms;
76 	} u;
77 };
78 
79 struct avtab_node {
80 	struct avtab_key key;
81 	struct avtab_datum datum;
82 	struct avtab_node *next;
83 };
84 
85 struct avtab {
86 	struct avtab_node **htable;
87 	u32 nel;	/* number of elements */
88 	u32 nslot;      /* number of hash slots */
89 	u16 mask;       /* mask to compute hash func */
90 
91 };
92 
93 int avtab_init(struct avtab *);
94 int avtab_alloc(struct avtab *, u32);
95 struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *k);
96 void avtab_destroy(struct avtab *h);
97 void avtab_hash_eval(struct avtab *h, char *tag);
98 
99 struct policydb;
100 int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
101 		    int (*insert)(struct avtab *a, struct avtab_key *k,
102 				  struct avtab_datum *d, void *p),
103 		    void *p);
104 
105 int avtab_read(struct avtab *a, void *fp, struct policydb *pol);
106 int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp);
107 int avtab_write(struct policydb *p, struct avtab *a, void *fp);
108 
109 struct avtab_node *avtab_insert_nonunique(struct avtab *h, struct avtab_key *key,
110 					  struct avtab_datum *datum);
111 
112 struct avtab_node *avtab_search_node(struct avtab *h, struct avtab_key *key);
113 
114 struct avtab_node *avtab_search_node_next(struct avtab_node *node, int specified);
115 
116 void avtab_cache_init(void);
117 void avtab_cache_destroy(void);
118 
119 #define MAX_AVTAB_HASH_BITS 11
120 #define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS)
121 
122 #endif	/* _SS_AVTAB_H_ */
123 
124