1/*
2 * A security context is a set of security attributes
3 * associated with each subject and object controlled
4 * by the security policy.  Security contexts are
5  * externally represented as variable-length strings
6 * that can be interpreted by a user or application
7 * with an understanding of the security policy.
8 * Internally, the security server uses a simple
9 * structure.  This structure is private to the
10 * security server and can be changed without affecting
11 * clients of the security server.
12 *
13 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
14 */
15#ifndef _SS_CONTEXT_H_
16#define _SS_CONTEXT_H_
17
18#include "ebitmap.h"
19#include "mls_types.h"
20#include "security.h"
21
22/*
23 * A security context consists of an authenticated user
24 * identity, a role, a type and a MLS range.
25 */
26struct context {
27	u32 user;
28	u32 role;
29	u32 type;
30	struct mls_range range;
31};
32
33static inline void mls_context_init(struct context *c)
34{
35	memset(&c->range, 0, sizeof(c->range));
36}
37
38static inline int mls_context_cpy(struct context *dst, struct context *src)
39{
40	int rc;
41
42	if (!selinux_mls_enabled)
43		return 0;
44
45	dst->range.level[0].sens = src->range.level[0].sens;
46	rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat);
47	if (rc)
48		goto out;
49
50	dst->range.level[1].sens = src->range.level[1].sens;
51	rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat);
52	if (rc)
53		ebitmap_destroy(&dst->range.level[0].cat);
54out:
55	return rc;
56}
57
58/*
59 * Sets both levels in the MLS range of 'dst' to the low level of 'src'.
60 */
61static inline int mls_context_cpy_low(struct context *dst, struct context *src)
62{
63	int rc;
64
65	if (!selinux_mls_enabled)
66		return 0;
67
68	dst->range.level[0].sens = src->range.level[0].sens;
69	rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat);
70	if (rc)
71		goto out;
72
73	dst->range.level[1].sens = src->range.level[0].sens;
74	rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[0].cat);
75	if (rc)
76		ebitmap_destroy(&dst->range.level[0].cat);
77out:
78	return rc;
79}
80
81static inline int mls_context_cmp(struct context *c1, struct context *c2)
82{
83	if (!selinux_mls_enabled)
84		return 1;
85
86	return ((c1->range.level[0].sens == c2->range.level[0].sens) &&
87		ebitmap_cmp(&c1->range.level[0].cat,&c2->range.level[0].cat) &&
88		(c1->range.level[1].sens == c2->range.level[1].sens) &&
89		ebitmap_cmp(&c1->range.level[1].cat,&c2->range.level[1].cat));
90}
91
92static inline void mls_context_destroy(struct context *c)
93{
94	if (!selinux_mls_enabled)
95		return;
96
97	ebitmap_destroy(&c->range.level[0].cat);
98	ebitmap_destroy(&c->range.level[1].cat);
99	mls_context_init(c);
100}
101
102static inline void context_init(struct context *c)
103{
104	memset(c, 0, sizeof(*c));
105}
106
107static inline int context_cpy(struct context *dst, struct context *src)
108{
109	dst->user = src->user;
110	dst->role = src->role;
111	dst->type = src->type;
112	return mls_context_cpy(dst, src);
113}
114
115static inline void context_destroy(struct context *c)
116{
117	c->user = c->role = c->type = 0;
118	mls_context_destroy(c);
119}
120
121static inline int context_cmp(struct context *c1, struct context *c2)
122{
123	return ((c1->user == c2->user) &&
124		(c1->role == c2->role) &&
125		(c1->type == c2->type) &&
126		mls_context_cmp(c1, c2));
127}
128
129#endif	/* _SS_CONTEXT_H_ */
130