1 /* SPDX-License-Identifier: GPL-2.0 */
3 * A security context is a set of security attributes
4 * associated with each subject and object controlled
5 * by the security policy. Security contexts are
6 * externally represented as variable-length strings
7 * that can be interpreted by a user or application
8 * with an understanding of the security policy.
9 * Internally, the security server uses a simple
10 * structure. This structure is private to the
11 * security server and can be changed without affecting
12 * clients of the security server.
14 * Author : Stephen Smalley, <stephen.smalley.work@gmail.com>
17 #ifndef _SS_CONTEXT_H_
18 #define _SS_CONTEXT_H_
21 #include "mls_types.h"
25 * A security context consists of an authenticated user
26 * identity, a role, a type and a MLS range.
32 u32 len; /* length of string in bytes */
33 struct mls_range range;
34 char *str; /* string representation if context cannot be mapped. */
37 static inline void mls_context_init(struct context *c)
39 memset(&c->range, 0, sizeof(c->range));
42 static inline int mls_context_cpy(struct context *dst,
43 const struct context *src)
47 dst->range.level[0].sens = src->range.level[0].sens;
48 rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat);
52 dst->range.level[1].sens = src->range.level[1].sens;
53 rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat);
55 ebitmap_destroy(&dst->range.level[0].cat);
61 * Sets both levels in the MLS range of 'dst' to the low level of 'src'.
63 static inline int mls_context_cpy_low(struct context *dst,
64 const struct context *src)
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);
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);
76 ebitmap_destroy(&dst->range.level[0].cat);
82 * Sets both levels in the MLS range of 'dst' to the high level of 'src'.
84 static inline int mls_context_cpy_high(struct context *dst,
85 const struct context *src)
89 dst->range.level[0].sens = src->range.level[1].sens;
90 rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[1].cat);
94 dst->range.level[1].sens = src->range.level[1].sens;
95 rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat);
97 ebitmap_destroy(&dst->range.level[0].cat);
102 static inline int mls_context_glblub(struct context *dst,
103 const struct context *c1,
104 const struct context *c2)
106 struct mls_range *dr = &dst->range;
107 const struct mls_range *r1 = &c1->range, *r2 = &c2->range;
110 if (r1->level[1].sens < r2->level[0].sens ||
111 r2->level[1].sens < r1->level[0].sens)
112 /* These ranges have no common sensitivities */
115 /* Take the greatest of the low */
116 dr->level[0].sens = max(r1->level[0].sens, r2->level[0].sens);
118 /* Take the least of the high */
119 dr->level[1].sens = min(r1->level[1].sens, r2->level[1].sens);
121 rc = ebitmap_and(&dr->level[0].cat, &r1->level[0].cat,
126 rc = ebitmap_and(&dr->level[1].cat, &r1->level[1].cat,
135 static inline int mls_context_cmp(const struct context *c1,
136 const struct context *c2)
138 return ((c1->range.level[0].sens == c2->range.level[0].sens) &&
139 ebitmap_cmp(&c1->range.level[0].cat, &c2->range.level[0].cat) &&
140 (c1->range.level[1].sens == c2->range.level[1].sens) &&
141 ebitmap_cmp(&c1->range.level[1].cat, &c2->range.level[1].cat));
144 static inline void mls_context_destroy(struct context *c)
146 ebitmap_destroy(&c->range.level[0].cat);
147 ebitmap_destroy(&c->range.level[1].cat);
151 static inline void context_init(struct context *c)
153 memset(c, 0, sizeof(*c));
156 static inline int context_cpy(struct context *dst, const struct context *src)
160 dst->user = src->user;
161 dst->role = src->role;
162 dst->type = src->type;
164 dst->str = kstrdup(src->str, GFP_ATOMIC);
172 rc = mls_context_cpy(dst, src);
182 static inline void context_destroy(struct context *c)
184 c->user = c->role = c->type = 0;
188 mls_context_destroy(c);
191 static inline int context_cmp(const struct context *c1,
192 const struct context *c2)
194 if (c1->len && c2->len)
195 return (c1->len == c2->len && !strcmp(c1->str, c2->str));
196 if (c1->len || c2->len)
198 return ((c1->user == c2->user) && (c1->role == c2->role) &&
199 (c1->type == c2->type) && mls_context_cmp(c1, c2));
202 u32 context_compute_hash(const struct context *c);
204 #endif /* _SS_CONTEXT_H_ */