blob: 212e3479a0d98e0b32b643ef78d97f5174b7f692 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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;
Eric Paris76f7ba32009-01-02 17:40:06 -050030 u32 len; /* length of string in bytes */
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 struct mls_range range;
Stephen Smalley12b29f32008-05-07 13:03:20 -040032 char *str; /* string representation if context cannot be mapped. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070033};
34
35static inline void mls_context_init(struct context *c)
36{
37 memset(&c->range, 0, sizeof(c->range));
38}
39
40static inline int mls_context_cpy(struct context *dst, struct context *src)
41{
42 int rc;
43
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 dst->range.level[0].sens = src->range.level[0].sens;
45 rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat);
46 if (rc)
47 goto out;
48
49 dst->range.level[1].sens = src->range.level[1].sens;
50 rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat);
51 if (rc)
52 ebitmap_destroy(&dst->range.level[0].cat);
53out:
54 return rc;
55}
56
Venkat Yekkirala0efc61e2006-12-12 13:02:41 -060057/*
58 * Sets both levels in the MLS range of 'dst' to the low level of 'src'.
59 */
60static inline int mls_context_cpy_low(struct context *dst, struct context *src)
61{
62 int rc;
63
Venkat Yekkirala0efc61e2006-12-12 13:02:41 -060064 dst->range.level[0].sens = src->range.level[0].sens;
65 rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat);
66 if (rc)
67 goto out;
68
69 dst->range.level[1].sens = src->range.level[0].sens;
70 rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[0].cat);
71 if (rc)
72 ebitmap_destroy(&dst->range.level[0].cat);
73out:
74 return rc;
75}
76
Eric Parisaa893262012-03-20 14:35:12 -040077/*
78 * Sets both levels in the MLS range of 'dst' to the high level of 'src'.
79 */
80static inline int mls_context_cpy_high(struct context *dst, struct context *src)
81{
82 int rc;
83
84 dst->range.level[0].sens = src->range.level[1].sens;
85 rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[1].cat);
86 if (rc)
87 goto out;
88
89 dst->range.level[1].sens = src->range.level[1].sens;
90 rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat);
91 if (rc)
92 ebitmap_destroy(&dst->range.level[0].cat);
93out:
94 return rc;
95}
96
Linus Torvalds1da177e2005-04-16 15:20:36 -070097static inline int mls_context_cmp(struct context *c1, struct context *c2)
98{
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 return ((c1->range.level[0].sens == c2->range.level[0].sens) &&
Eric Paris81fa42d2008-04-22 17:46:13 -0400100 ebitmap_cmp(&c1->range.level[0].cat, &c2->range.level[0].cat) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 (c1->range.level[1].sens == c2->range.level[1].sens) &&
Eric Paris81fa42d2008-04-22 17:46:13 -0400102 ebitmap_cmp(&c1->range.level[1].cat, &c2->range.level[1].cat));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103}
104
105static inline void mls_context_destroy(struct context *c)
106{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 ebitmap_destroy(&c->range.level[0].cat);
108 ebitmap_destroy(&c->range.level[1].cat);
109 mls_context_init(c);
110}
111
112static inline void context_init(struct context *c)
113{
114 memset(c, 0, sizeof(*c));
115}
116
117static inline int context_cpy(struct context *dst, struct context *src)
118{
Stephen Smalley12b29f32008-05-07 13:03:20 -0400119 int rc;
120
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 dst->user = src->user;
122 dst->role = src->role;
123 dst->type = src->type;
Stephen Smalley12b29f32008-05-07 13:03:20 -0400124 if (src->str) {
125 dst->str = kstrdup(src->str, GFP_ATOMIC);
126 if (!dst->str)
127 return -ENOMEM;
128 dst->len = src->len;
129 } else {
130 dst->str = NULL;
131 dst->len = 0;
132 }
133 rc = mls_context_cpy(dst, src);
134 if (rc) {
135 kfree(dst->str);
136 return rc;
137 }
138 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139}
140
141static inline void context_destroy(struct context *c)
142{
143 c->user = c->role = c->type = 0;
Stephen Smalley12b29f32008-05-07 13:03:20 -0400144 kfree(c->str);
145 c->str = NULL;
146 c->len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 mls_context_destroy(c);
148}
149
150static inline int context_cmp(struct context *c1, struct context *c2)
151{
Stephen Smalley12b29f32008-05-07 13:03:20 -0400152 if (c1->len && c2->len)
153 return (c1->len == c2->len && !strcmp(c1->str, c2->str));
154 if (c1->len || c2->len)
155 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 return ((c1->user == c2->user) &&
157 (c1->role == c2->role) &&
158 (c1->type == c2->type) &&
159 mls_context_cmp(c1, c2));
160}
161
162#endif /* _SS_CONTEXT_H_ */
163