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 *
140fe53224SStephen Smalley * Author : Stephen Smalley, <stephen.smalley.work@gmail.com>
151da177e4SLinus Torvalds */
16*b27e564cSPaul Moore
171da177e4SLinus Torvalds #ifndef _SS_CONTEXT_H_
181da177e4SLinus Torvalds #define _SS_CONTEXT_H_
191da177e4SLinus Torvalds
201da177e4SLinus Torvalds #include "ebitmap.h"
211da177e4SLinus Torvalds #include "mls_types.h"
221da177e4SLinus Torvalds #include "security.h"
231da177e4SLinus Torvalds
241da177e4SLinus Torvalds /*
251da177e4SLinus Torvalds * A security context consists of an authenticated user
261da177e4SLinus Torvalds * identity, a role, a type and a MLS range.
271da177e4SLinus Torvalds */
281da177e4SLinus Torvalds struct context {
291da177e4SLinus Torvalds u32 user;
301da177e4SLinus Torvalds u32 role;
311da177e4SLinus Torvalds u32 type;
3276f7ba35SEric Paris u32 len; /* length of string in bytes */
331da177e4SLinus Torvalds struct mls_range range;
3412b29f34SStephen Smalley char *str; /* string representation if context cannot be mapped. */
351da177e4SLinus Torvalds };
361da177e4SLinus Torvalds
mls_context_init(struct context * c)371da177e4SLinus Torvalds static inline void mls_context_init(struct context *c)
381da177e4SLinus Torvalds {
391da177e4SLinus Torvalds memset(&c->range, 0, sizeof(c->range));
401da177e4SLinus Torvalds }
411da177e4SLinus Torvalds
mls_context_cpy(struct context * dst,const struct context * src)42*b27e564cSPaul Moore static inline int mls_context_cpy(struct context *dst,
43*b27e564cSPaul Moore const struct context *src)
441da177e4SLinus Torvalds {
451da177e4SLinus Torvalds int rc;
461da177e4SLinus Torvalds
471da177e4SLinus Torvalds dst->range.level[0].sens = src->range.level[0].sens;
481da177e4SLinus Torvalds rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat);
491da177e4SLinus Torvalds if (rc)
501da177e4SLinus Torvalds goto out;
511da177e4SLinus Torvalds
521da177e4SLinus Torvalds dst->range.level[1].sens = src->range.level[1].sens;
531da177e4SLinus Torvalds rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat);
541da177e4SLinus Torvalds if (rc)
551da177e4SLinus Torvalds ebitmap_destroy(&dst->range.level[0].cat);
561da177e4SLinus Torvalds out:
571da177e4SLinus Torvalds return rc;
581da177e4SLinus Torvalds }
591da177e4SLinus Torvalds
600efc61eaSVenkat Yekkirala /*
610efc61eaSVenkat Yekkirala * Sets both levels in the MLS range of 'dst' to the low level of 'src'.
620efc61eaSVenkat Yekkirala */
mls_context_cpy_low(struct context * dst,const struct context * src)63*b27e564cSPaul Moore static inline int mls_context_cpy_low(struct context *dst,
64*b27e564cSPaul Moore const struct context *src)
650efc61eaSVenkat Yekkirala {
660efc61eaSVenkat Yekkirala int rc;
670efc61eaSVenkat Yekkirala
680efc61eaSVenkat Yekkirala dst->range.level[0].sens = src->range.level[0].sens;
690efc61eaSVenkat Yekkirala rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat);
700efc61eaSVenkat Yekkirala if (rc)
710efc61eaSVenkat Yekkirala goto out;
720efc61eaSVenkat Yekkirala
730efc61eaSVenkat Yekkirala dst->range.level[1].sens = src->range.level[0].sens;
740efc61eaSVenkat Yekkirala rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[0].cat);
750efc61eaSVenkat Yekkirala if (rc)
760efc61eaSVenkat Yekkirala ebitmap_destroy(&dst->range.level[0].cat);
770efc61eaSVenkat Yekkirala out:
780efc61eaSVenkat Yekkirala return rc;
790efc61eaSVenkat Yekkirala }
800efc61eaSVenkat Yekkirala
81aa893269SEric Paris /*
82aa893269SEric Paris * Sets both levels in the MLS range of 'dst' to the high level of 'src'.
83aa893269SEric Paris */
mls_context_cpy_high(struct context * dst,const struct context * src)84*b27e564cSPaul Moore static inline int mls_context_cpy_high(struct context *dst,
85*b27e564cSPaul Moore const struct context *src)
86aa893269SEric Paris {
87aa893269SEric Paris int rc;
88aa893269SEric Paris
89aa893269SEric Paris dst->range.level[0].sens = src->range.level[1].sens;
90aa893269SEric Paris rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[1].cat);
91aa893269SEric Paris if (rc)
92aa893269SEric Paris goto out;
93aa893269SEric Paris
94aa893269SEric Paris dst->range.level[1].sens = src->range.level[1].sens;
95aa893269SEric Paris rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat);
96aa893269SEric Paris if (rc)
97aa893269SEric Paris ebitmap_destroy(&dst->range.level[0].cat);
98aa893269SEric Paris out:
99aa893269SEric Paris return rc;
100aa893269SEric Paris }
101aa893269SEric Paris
mls_context_glblub(struct context * dst,const struct context * c1,const struct context * c2)10242345b68SJoshua Brindle static inline int mls_context_glblub(struct context *dst,
103*b27e564cSPaul Moore const struct context *c1,
104*b27e564cSPaul Moore const struct context *c2)
10542345b68SJoshua Brindle {
1066354324dSChristian Göttsche struct mls_range *dr = &dst->range;
1076354324dSChristian Göttsche const struct mls_range *r1 = &c1->range, *r2 = &c2->range;
10842345b68SJoshua Brindle int rc = 0;
10942345b68SJoshua Brindle
11042345b68SJoshua Brindle if (r1->level[1].sens < r2->level[0].sens ||
11142345b68SJoshua Brindle r2->level[1].sens < r1->level[0].sens)
11242345b68SJoshua Brindle /* These ranges have no common sensitivities */
11342345b68SJoshua Brindle return -EINVAL;
11442345b68SJoshua Brindle
11542345b68SJoshua Brindle /* Take the greatest of the low */
11642345b68SJoshua Brindle dr->level[0].sens = max(r1->level[0].sens, r2->level[0].sens);
11742345b68SJoshua Brindle
11842345b68SJoshua Brindle /* Take the least of the high */
11942345b68SJoshua Brindle dr->level[1].sens = min(r1->level[1].sens, r2->level[1].sens);
12042345b68SJoshua Brindle
121*b27e564cSPaul Moore rc = ebitmap_and(&dr->level[0].cat, &r1->level[0].cat,
122*b27e564cSPaul Moore &r2->level[0].cat);
12342345b68SJoshua Brindle if (rc)
12442345b68SJoshua Brindle goto out;
12542345b68SJoshua Brindle
126*b27e564cSPaul Moore rc = ebitmap_and(&dr->level[1].cat, &r1->level[1].cat,
127*b27e564cSPaul Moore &r2->level[1].cat);
12842345b68SJoshua Brindle if (rc)
12942345b68SJoshua Brindle goto out;
13042345b68SJoshua Brindle
13142345b68SJoshua Brindle out:
13242345b68SJoshua Brindle return rc;
13342345b68SJoshua Brindle }
13442345b68SJoshua Brindle
mls_context_cmp(const struct context * c1,const struct context * c2)135*b27e564cSPaul Moore static inline int mls_context_cmp(const struct context *c1,
136*b27e564cSPaul Moore const struct context *c2)
1371da177e4SLinus Torvalds {
1381da177e4SLinus Torvalds return ((c1->range.level[0].sens == c2->range.level[0].sens) &&
1391da177e4SLinus Torvalds ebitmap_cmp(&c1->range.level[0].cat, &c2->range.level[0].cat) &&
1401da177e4SLinus Torvalds (c1->range.level[1].sens == c2->range.level[1].sens) &&
1411da177e4SLinus Torvalds ebitmap_cmp(&c1->range.level[1].cat, &c2->range.level[1].cat));
1421da177e4SLinus Torvalds }
1431da177e4SLinus Torvalds
mls_context_destroy(struct context * c)1441da177e4SLinus Torvalds static inline void mls_context_destroy(struct context *c)
1451da177e4SLinus Torvalds {
1461da177e4SLinus Torvalds ebitmap_destroy(&c->range.level[0].cat);
1471da177e4SLinus Torvalds ebitmap_destroy(&c->range.level[1].cat);
1481da177e4SLinus Torvalds mls_context_init(c);
1491da177e4SLinus Torvalds }
1501da177e4SLinus Torvalds
context_init(struct context * c)1511da177e4SLinus Torvalds static inline void context_init(struct context *c)
1521da177e4SLinus Torvalds {
1531da177e4SLinus Torvalds memset(c, 0, sizeof(*c));
1541da177e4SLinus Torvalds }
1551da177e4SLinus Torvalds
context_cpy(struct context * dst,const struct context * src)1566354324dSChristian Göttsche static inline int context_cpy(struct context *dst, const struct context *src)
1571da177e4SLinus Torvalds {
15812b29f34SStephen Smalley int rc;
15912b29f34SStephen Smalley
1601da177e4SLinus Torvalds dst->user = src->user;
1611da177e4SLinus Torvalds dst->role = src->role;
1621da177e4SLinus Torvalds dst->type = src->type;
16312b29f34SStephen Smalley if (src->str) {
16412b29f34SStephen Smalley dst->str = kstrdup(src->str, GFP_ATOMIC);
16512b29f34SStephen Smalley if (!dst->str)
16612b29f34SStephen Smalley return -ENOMEM;
16712b29f34SStephen Smalley dst->len = src->len;
16812b29f34SStephen Smalley } else {
16912b29f34SStephen Smalley dst->str = NULL;
17012b29f34SStephen Smalley dst->len = 0;
17112b29f34SStephen Smalley }
17212b29f34SStephen Smalley rc = mls_context_cpy(dst, src);
17312b29f34SStephen Smalley if (rc) {
17412b29f34SStephen Smalley kfree(dst->str);
17553f3517aSChristian Göttsche dst->str = NULL;
176ed99135fSChristian Göttsche dst->len = 0;
17712b29f34SStephen Smalley return rc;
17812b29f34SStephen Smalley }
17912b29f34SStephen Smalley return 0;
1801da177e4SLinus Torvalds }
1811da177e4SLinus Torvalds
context_destroy(struct context * c)1821da177e4SLinus Torvalds static inline void context_destroy(struct context *c)
1831da177e4SLinus Torvalds {
184225621c9SOndrej Mosnacek c->user = c->role = c->type = 0;
18512b29f34SStephen Smalley kfree(c->str);
18612b29f34SStephen Smalley c->str = NULL;
18712b29f34SStephen Smalley c->len = 0;
1881da177e4SLinus Torvalds mls_context_destroy(c);
1891da177e4SLinus Torvalds }
1901da177e4SLinus Torvalds
context_cmp(const struct context * c1,const struct context * c2)191*b27e564cSPaul Moore static inline int context_cmp(const struct context *c1,
192*b27e564cSPaul Moore const struct context *c2)
1931da177e4SLinus Torvalds {
19412b29f34SStephen Smalley if (c1->len && c2->len)
19512b29f34SStephen Smalley return (c1->len == c2->len && !strcmp(c1->str, c2->str));
19612b29f34SStephen Smalley if (c1->len || c2->len)
19712b29f34SStephen Smalley return 0;
198*b27e564cSPaul Moore return ((c1->user == c2->user) && (c1->role == c2->role) &&
199*b27e564cSPaul Moore (c1->type == c2->type) && mls_context_cmp(c1, c2));
2001da177e4SLinus Torvalds }
2011da177e4SLinus Torvalds
20250077289SOndrej Mosnacek u32 context_compute_hash(const struct context *c);
20350077289SOndrej Mosnacek
2041da177e4SLinus Torvalds #endif /* _SS_CONTEXT_H_ */
205