xref: /openbmc/linux/security/selinux/ss/avtab.h (revision d4295e12)
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@tycho.nsa.gov>
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 #include <linux/flex_array.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		0x0001
34 #define AVTAB_AUDITALLOW	0x0002
35 #define AVTAB_AUDITDENY		0x0004
36 #define AVTAB_AV		(AVTAB_ALLOWED | AVTAB_AUDITALLOW | AVTAB_AUDITDENY)
37 #define AVTAB_TRANSITION	0x0010
38 #define AVTAB_MEMBER		0x0020
39 #define AVTAB_CHANGE		0x0040
40 #define AVTAB_TYPE		(AVTAB_TRANSITION | AVTAB_MEMBER | AVTAB_CHANGE)
41 /* extended permissions */
42 #define AVTAB_XPERMS_ALLOWED	0x0100
43 #define AVTAB_XPERMS_AUDITALLOW	0x0200
44 #define AVTAB_XPERMS_DONTAUDIT	0x0400
45 #define AVTAB_XPERMS		(AVTAB_XPERMS_ALLOWED | \
46 				AVTAB_XPERMS_AUDITALLOW | \
47 				AVTAB_XPERMS_DONTAUDIT)
48 #define AVTAB_ENABLED_OLD   0x80000000 /* reserved for used in cond_avtab */
49 #define AVTAB_ENABLED		0x8000 /* reserved for used in cond_avtab */
50 	u16 specified;	/* what field is specified */
51 };
52 
53 /*
54  * For operations that require more than the 32 permissions provided by the avc
55  * extended permissions may be used to provide 256 bits of permissions.
56  */
57 struct avtab_extended_perms {
58 /* These are not flags. All 256 values may be used */
59 #define AVTAB_XPERMS_IOCTLFUNCTION	0x01
60 #define AVTAB_XPERMS_IOCTLDRIVER	0x02
61 	/* extension of the avtab_key specified */
62 	u8 specified; /* ioctl, netfilter, ... */
63 	/*
64 	 * if 256 bits is not adequate as is often the case with ioctls, then
65 	 * multiple extended perms may be used and the driver field
66 	 * specifies which permissions are included.
67 	 */
68 	u8 driver;
69 	/* 256 bits of permissions */
70 	struct extended_perms_data perms;
71 };
72 
73 struct avtab_datum {
74 	union {
75 		u32 data; /* access vector or type value */
76 		struct avtab_extended_perms *xperms;
77 	} u;
78 };
79 
80 struct avtab_node {
81 	struct avtab_key key;
82 	struct avtab_datum datum;
83 	struct avtab_node *next;
84 };
85 
86 struct avtab {
87 	struct flex_array *htable;
88 	u32 nel;	/* number of elements */
89 	u32 nslot;      /* number of hash slots */
90 	u32 mask;       /* mask to compute hash func */
91 
92 };
93 
94 int avtab_init(struct avtab *);
95 int avtab_alloc(struct avtab *, u32);
96 struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *k);
97 void avtab_destroy(struct avtab *h);
98 void avtab_hash_eval(struct avtab *h, char *tag);
99 
100 struct policydb;
101 int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
102 		    int (*insert)(struct avtab *a, struct avtab_key *k,
103 				  struct avtab_datum *d, void *p),
104 		    void *p);
105 
106 int avtab_read(struct avtab *a, void *fp, struct policydb *pol);
107 int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp);
108 int avtab_write(struct policydb *p, struct avtab *a, void *fp);
109 
110 struct avtab_node *avtab_insert_nonunique(struct avtab *h, struct avtab_key *key,
111 					  struct avtab_datum *datum);
112 
113 struct avtab_node *avtab_search_node(struct avtab *h, struct avtab_key *key);
114 
115 struct avtab_node *avtab_search_node_next(struct avtab_node *node, int specified);
116 
117 #define MAX_AVTAB_HASH_BITS 16
118 #define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS)
119 
120 #endif	/* _SS_AVTAB_H_ */
121 
122