1b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */
21da177e4SLinus Torvalds /*
31da177e4SLinus Torvalds * A security context is a set of security attributes
41da177e4SLinus Torvalds * associated with each subject and object controlled
51da177e4SLinus Torvalds * by the security policy. Security contexts are
61da177e4SLinus Torvalds * externally represented as variable-length strings
71da177e4SLinus Torvalds * that can be interpreted by a user or application
81da177e4SLinus Torvalds * with an understanding of the security policy.
91da177e4SLinus Torvalds * Internally, the security server uses a simple
101da177e4SLinus Torvalds * structure. This structure is private to the
111da177e4SLinus Torvalds * security server and can be changed without affecting
121da177e4SLinus Torvalds * clients of the security server.
131da177e4SLinus Torvalds *
14*0fe53224SStephen Smalley * Author : Stephen Smalley, <stephen.smalley.work@gmail.com>
151da177e4SLinus Torvalds */
161da177e4SLinus Torvalds #ifndef _SS_CONTEXT_H_
171da177e4SLinus Torvalds #define _SS_CONTEXT_H_
181da177e4SLinus Torvalds
191da177e4SLinus Torvalds #include "ebitmap.h"
201da177e4SLinus Torvalds #include "mls_types.h"
211da177e4SLinus Torvalds #include "security.h"
221da177e4SLinus Torvalds
231da177e4SLinus Torvalds /*
241da177e4SLinus Torvalds * A security context consists of an authenticated user
251da177e4SLinus Torvalds * identity, a role, a type and a MLS range.
261da177e4SLinus Torvalds */
271da177e4SLinus Torvalds struct context {
281da177e4SLinus Torvalds u32 user;
291da177e4SLinus Torvalds u32 role;
301da177e4SLinus Torvalds u32 type;
3176f7ba35SEric Paris u32 len; /* length of string in bytes */
321da177e4SLinus Torvalds struct mls_range range;
3312b29f34SStephen Smalley char *str; /* string representation if context cannot be mapped. */
341da177e4SLinus Torvalds };
351da177e4SLinus Torvalds
mls_context_init(struct context * c)361da177e4SLinus Torvalds static inline void mls_context_init(struct context *c)
371da177e4SLinus Torvalds {
381da177e4SLinus Torvalds memset(&c->range, 0, sizeof(c->range));
391da177e4SLinus Torvalds }
401da177e4SLinus Torvalds
mls_context_cpy(struct context * dst,const struct context * src)416354324dSChristian Göttsche static inline int mls_context_cpy(struct context *dst, const struct context *src)
421da177e4SLinus Torvalds {
431da177e4SLinus Torvalds int rc;
441da177e4SLinus Torvalds
451da177e4SLinus Torvalds dst->range.level[0].sens = src->range.level[0].sens;
461da177e4SLinus Torvalds rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat);
471da177e4SLinus Torvalds if (rc)
481da177e4SLinus Torvalds goto out;
491da177e4SLinus Torvalds
501da177e4SLinus Torvalds dst->range.level[1].sens = src->range.level[1].sens;
511da177e4SLinus Torvalds rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat);
521da177e4SLinus Torvalds if (rc)
531da177e4SLinus Torvalds ebitmap_destroy(&dst->range.level[0].cat);
541da177e4SLinus Torvalds out:
551da177e4SLinus Torvalds return rc;
561da177e4SLinus Torvalds }
571da177e4SLinus Torvalds
580efc61eaSVenkat Yekkirala /*
590efc61eaSVenkat Yekkirala * Sets both levels in the MLS range of 'dst' to the low level of 'src'.
600efc61eaSVenkat Yekkirala */
mls_context_cpy_low(struct context * dst,const struct context * src)616354324dSChristian Göttsche static inline int mls_context_cpy_low(struct context *dst, const struct context *src)
620efc61eaSVenkat Yekkirala {
630efc61eaSVenkat Yekkirala int rc;
640efc61eaSVenkat Yekkirala
650efc61eaSVenkat Yekkirala dst->range.level[0].sens = src->range.level[0].sens;
660efc61eaSVenkat Yekkirala rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat);
670efc61eaSVenkat Yekkirala if (rc)
680efc61eaSVenkat Yekkirala goto out;
690efc61eaSVenkat Yekkirala
700efc61eaSVenkat Yekkirala dst->range.level[1].sens = src->range.level[0].sens;
710efc61eaSVenkat Yekkirala rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[0].cat);
720efc61eaSVenkat Yekkirala if (rc)
730efc61eaSVenkat Yekkirala ebitmap_destroy(&dst->range.level[0].cat);
740efc61eaSVenkat Yekkirala out:
750efc61eaSVenkat Yekkirala return rc;
760efc61eaSVenkat Yekkirala }
770efc61eaSVenkat Yekkirala
78aa893269SEric Paris /*
79aa893269SEric Paris * Sets both levels in the MLS range of 'dst' to the high level of 'src'.
80aa893269SEric Paris */
mls_context_cpy_high(struct context * dst,const struct context * src)816354324dSChristian Göttsche static inline int mls_context_cpy_high(struct context *dst, const struct context *src)
82aa893269SEric Paris {
83aa893269SEric Paris int rc;
84aa893269SEric Paris
85aa893269SEric Paris dst->range.level[0].sens = src->range.level[1].sens;
86aa893269SEric Paris rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[1].cat);
87aa893269SEric Paris if (rc)
88aa893269SEric Paris goto out;
89aa893269SEric Paris
90aa893269SEric Paris dst->range.level[1].sens = src->range.level[1].sens;
91aa893269SEric Paris rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat);
92aa893269SEric Paris if (rc)
93aa893269SEric Paris ebitmap_destroy(&dst->range.level[0].cat);
94aa893269SEric Paris out:
95aa893269SEric Paris return rc;
96aa893269SEric Paris }
97aa893269SEric Paris
9842345b68SJoshua Brindle
mls_context_glblub(struct context * dst,const struct context * c1,const struct context * c2)9942345b68SJoshua Brindle static inline int mls_context_glblub(struct context *dst,
1006354324dSChristian Göttsche const struct context *c1, const struct context *c2)
10142345b68SJoshua Brindle {
1026354324dSChristian Göttsche struct mls_range *dr = &dst->range;
1036354324dSChristian Göttsche const struct mls_range *r1 = &c1->range, *r2 = &c2->range;
10442345b68SJoshua Brindle int rc = 0;
10542345b68SJoshua Brindle
10642345b68SJoshua Brindle if (r1->level[1].sens < r2->level[0].sens ||
10742345b68SJoshua Brindle r2->level[1].sens < r1->level[0].sens)
10842345b68SJoshua Brindle /* These ranges have no common sensitivities */
10942345b68SJoshua Brindle return -EINVAL;
11042345b68SJoshua Brindle
11142345b68SJoshua Brindle /* Take the greatest of the low */
11242345b68SJoshua Brindle dr->level[0].sens = max(r1->level[0].sens, r2->level[0].sens);
11342345b68SJoshua Brindle
11442345b68SJoshua Brindle /* Take the least of the high */
11542345b68SJoshua Brindle dr->level[1].sens = min(r1->level[1].sens, r2->level[1].sens);
11642345b68SJoshua Brindle
11742345b68SJoshua Brindle rc = ebitmap_and(&dr->level[0].cat,
11842345b68SJoshua Brindle &r1->level[0].cat, &r2->level[0].cat);
11942345b68SJoshua Brindle if (rc)
12042345b68SJoshua Brindle goto out;
12142345b68SJoshua Brindle
12242345b68SJoshua Brindle rc = ebitmap_and(&dr->level[1].cat,
12342345b68SJoshua Brindle &r1->level[1].cat, &r2->level[1].cat);
12442345b68SJoshua Brindle if (rc)
12542345b68SJoshua Brindle goto out;
12642345b68SJoshua Brindle
12742345b68SJoshua Brindle out:
12842345b68SJoshua Brindle return rc;
12942345b68SJoshua Brindle }
13042345b68SJoshua Brindle
mls_context_cmp(const struct context * c1,const struct context * c2)1316354324dSChristian Göttsche static inline int mls_context_cmp(const struct context *c1, const struct context *c2)
1321da177e4SLinus Torvalds {
1331da177e4SLinus Torvalds return ((c1->range.level[0].sens == c2->range.level[0].sens) &&
1341da177e4SLinus Torvalds ebitmap_cmp(&c1->range.level[0].cat, &c2->range.level[0].cat) &&
1351da177e4SLinus Torvalds (c1->range.level[1].sens == c2->range.level[1].sens) &&
1361da177e4SLinus Torvalds ebitmap_cmp(&c1->range.level[1].cat, &c2->range.level[1].cat));
1371da177e4SLinus Torvalds }
1381da177e4SLinus Torvalds
mls_context_destroy(struct context * c)1391da177e4SLinus Torvalds static inline void mls_context_destroy(struct context *c)
1401da177e4SLinus Torvalds {
1411da177e4SLinus Torvalds ebitmap_destroy(&c->range.level[0].cat);
1421da177e4SLinus Torvalds ebitmap_destroy(&c->range.level[1].cat);
1431da177e4SLinus Torvalds mls_context_init(c);
1441da177e4SLinus Torvalds }
1451da177e4SLinus Torvalds
context_init(struct context * c)1461da177e4SLinus Torvalds static inline void context_init(struct context *c)
1471da177e4SLinus Torvalds {
1481da177e4SLinus Torvalds memset(c, 0, sizeof(*c));
1491da177e4SLinus Torvalds }
1501da177e4SLinus Torvalds
context_cpy(struct context * dst,const struct context * src)1516354324dSChristian Göttsche static inline int context_cpy(struct context *dst, const struct context *src)
1521da177e4SLinus Torvalds {
15312b29f34SStephen Smalley int rc;
15412b29f34SStephen Smalley
1551da177e4SLinus Torvalds dst->user = src->user;
1561da177e4SLinus Torvalds dst->role = src->role;
1571da177e4SLinus Torvalds dst->type = src->type;
15812b29f34SStephen Smalley if (src->str) {
15912b29f34SStephen Smalley dst->str = kstrdup(src->str, GFP_ATOMIC);
16012b29f34SStephen Smalley if (!dst->str)
16112b29f34SStephen Smalley return -ENOMEM;
16212b29f34SStephen Smalley dst->len = src->len;
16312b29f34SStephen Smalley } else {
16412b29f34SStephen Smalley dst->str = NULL;
16512b29f34SStephen Smalley dst->len = 0;
16612b29f34SStephen Smalley }
16712b29f34SStephen Smalley rc = mls_context_cpy(dst, src);
16812b29f34SStephen Smalley if (rc) {
16912b29f34SStephen Smalley kfree(dst->str);
17053f3517aSChristian Göttsche dst->str = NULL;
171ed99135fSChristian Göttsche dst->len = 0;
17212b29f34SStephen Smalley return rc;
17312b29f34SStephen Smalley }
17412b29f34SStephen Smalley return 0;
1751da177e4SLinus Torvalds }
1761da177e4SLinus Torvalds
context_destroy(struct context * c)1771da177e4SLinus Torvalds static inline void context_destroy(struct context *c)
1781da177e4SLinus Torvalds {
179225621c9SOndrej Mosnacek c->user = c->role = c->type = 0;
18012b29f34SStephen Smalley kfree(c->str);
18112b29f34SStephen Smalley c->str = NULL;
18212b29f34SStephen Smalley c->len = 0;
1831da177e4SLinus Torvalds mls_context_destroy(c);
1841da177e4SLinus Torvalds }
1851da177e4SLinus Torvalds
context_cmp(const struct context * c1,const struct context * c2)1866354324dSChristian Göttsche static inline int context_cmp(const struct context *c1, const struct context *c2)
1871da177e4SLinus Torvalds {
18812b29f34SStephen Smalley if (c1->len && c2->len)
18912b29f34SStephen Smalley return (c1->len == c2->len && !strcmp(c1->str, c2->str));
19012b29f34SStephen Smalley if (c1->len || c2->len)
19112b29f34SStephen Smalley return 0;
1921da177e4SLinus Torvalds return ((c1->user == c2->user) &&
1931da177e4SLinus Torvalds (c1->role == c2->role) &&
1941da177e4SLinus Torvalds (c1->type == c2->type) &&
1951da177e4SLinus Torvalds mls_context_cmp(c1, c2));
1961da177e4SLinus Torvalds }
1971da177e4SLinus Torvalds
19850077289SOndrej Mosnacek u32 context_compute_hash(const struct context *c);
19950077289SOndrej Mosnacek
2001da177e4SLinus Torvalds #endif /* _SS_CONTEXT_H_ */
2011da177e4SLinus Torvalds
202