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>
16 #ifndef _SS_CONTEXT_H_
17 #define _SS_CONTEXT_H_
20 #include "mls_types.h"
24 * A security context consists of an authenticated user
25 * identity, a role, a type and a MLS range.
31 u32 len; /* length of string in bytes */
32 struct mls_range range;
33 char *str; /* string representation if context cannot be mapped. */
36 static inline void mls_context_init(struct context *c)
38 memset(&c->range, 0, sizeof(c->range));
41 static inline int mls_context_cpy(struct context *dst, const struct context *src)
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);
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);
53 ebitmap_destroy(&dst->range.level[0].cat);
59 * Sets both levels in the MLS range of 'dst' to the low level of 'src'.
61 static inline int mls_context_cpy_low(struct context *dst, const struct context *src)
65 dst->range.level[0].sens = src->range.level[0].sens;
66 rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat);
70 dst->range.level[1].sens = src->range.level[0].sens;
71 rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[0].cat);
73 ebitmap_destroy(&dst->range.level[0].cat);
79 * Sets both levels in the MLS range of 'dst' to the high level of 'src'.
81 static inline int mls_context_cpy_high(struct context *dst, const struct context *src)
85 dst->range.level[0].sens = src->range.level[1].sens;
86 rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[1].cat);
90 dst->range.level[1].sens = src->range.level[1].sens;
91 rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat);
93 ebitmap_destroy(&dst->range.level[0].cat);
99 static inline int mls_context_glblub(struct context *dst,
100 const struct context *c1, const struct context *c2)
102 struct mls_range *dr = &dst->range;
103 const struct mls_range *r1 = &c1->range, *r2 = &c2->range;
106 if (r1->level[1].sens < r2->level[0].sens ||
107 r2->level[1].sens < r1->level[0].sens)
108 /* These ranges have no common sensitivities */
111 /* Take the greatest of the low */
112 dr->level[0].sens = max(r1->level[0].sens, r2->level[0].sens);
114 /* Take the least of the high */
115 dr->level[1].sens = min(r1->level[1].sens, r2->level[1].sens);
117 rc = ebitmap_and(&dr->level[0].cat,
118 &r1->level[0].cat, &r2->level[0].cat);
122 rc = ebitmap_and(&dr->level[1].cat,
123 &r1->level[1].cat, &r2->level[1].cat);
131 static inline int mls_context_cmp(const struct context *c1, const struct context *c2)
133 return ((c1->range.level[0].sens == c2->range.level[0].sens) &&
134 ebitmap_cmp(&c1->range.level[0].cat, &c2->range.level[0].cat) &&
135 (c1->range.level[1].sens == c2->range.level[1].sens) &&
136 ebitmap_cmp(&c1->range.level[1].cat, &c2->range.level[1].cat));
139 static inline void mls_context_destroy(struct context *c)
141 ebitmap_destroy(&c->range.level[0].cat);
142 ebitmap_destroy(&c->range.level[1].cat);
146 static inline void context_init(struct context *c)
148 memset(c, 0, sizeof(*c));
151 static inline int context_cpy(struct context *dst, const struct context *src)
155 dst->user = src->user;
156 dst->role = src->role;
157 dst->type = src->type;
159 dst->str = kstrdup(src->str, GFP_ATOMIC);
167 rc = mls_context_cpy(dst, src);
177 static inline void context_destroy(struct context *c)
179 c->user = c->role = c->type = 0;
183 mls_context_destroy(c);
186 static inline int context_cmp(const struct context *c1, const struct context *c2)
188 if (c1->len && c2->len)
189 return (c1->len == c2->len && !strcmp(c1->str, c2->str));
190 if (c1->len || c2->len)
192 return ((c1->user == c2->user) &&
193 (c1->role == c2->role) &&
194 (c1->type == c2->type) &&
195 mls_context_cmp(c1, c2));
198 u32 context_compute_hash(const struct context *c);
200 #endif /* _SS_CONTEXT_H_ */