forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
198 lines
4.8 KiB
198 lines
4.8 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
|
/* |
|
* A security context is a set of security attributes |
|
* associated with each subject and object controlled |
|
* by the security policy. Security contexts are |
|
* externally represented as variable-length strings |
|
* that can be interpreted by a user or application |
|
* with an understanding of the security policy. |
|
* Internally, the security server uses a simple |
|
* structure. This structure is private to the |
|
* security server and can be changed without affecting |
|
* clients of the security server. |
|
* |
|
* Author : Stephen Smalley, <[email protected]> |
|
*/ |
|
#ifndef _SS_CONTEXT_H_ |
|
#define _SS_CONTEXT_H_ |
|
|
|
#include "ebitmap.h" |
|
#include "mls_types.h" |
|
#include "security.h" |
|
|
|
/* |
|
* A security context consists of an authenticated user |
|
* identity, a role, a type and a MLS range. |
|
*/ |
|
struct context { |
|
u32 user; |
|
u32 role; |
|
u32 type; |
|
u32 len; /* length of string in bytes */ |
|
struct mls_range range; |
|
char *str; /* string representation if context cannot be mapped. */ |
|
}; |
|
|
|
static inline void mls_context_init(struct context *c) |
|
{ |
|
memset(&c->range, 0, sizeof(c->range)); |
|
} |
|
|
|
static inline int mls_context_cpy(struct context *dst, struct context *src) |
|
{ |
|
int rc; |
|
|
|
dst->range.level[0].sens = src->range.level[0].sens; |
|
rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat); |
|
if (rc) |
|
goto out; |
|
|
|
dst->range.level[1].sens = src->range.level[1].sens; |
|
rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat); |
|
if (rc) |
|
ebitmap_destroy(&dst->range.level[0].cat); |
|
out: |
|
return rc; |
|
} |
|
|
|
/* |
|
* Sets both levels in the MLS range of 'dst' to the low level of 'src'. |
|
*/ |
|
static inline int mls_context_cpy_low(struct context *dst, struct context *src) |
|
{ |
|
int rc; |
|
|
|
dst->range.level[0].sens = src->range.level[0].sens; |
|
rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat); |
|
if (rc) |
|
goto out; |
|
|
|
dst->range.level[1].sens = src->range.level[0].sens; |
|
rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[0].cat); |
|
if (rc) |
|
ebitmap_destroy(&dst->range.level[0].cat); |
|
out: |
|
return rc; |
|
} |
|
|
|
/* |
|
* Sets both levels in the MLS range of 'dst' to the high level of 'src'. |
|
*/ |
|
static inline int mls_context_cpy_high(struct context *dst, struct context *src) |
|
{ |
|
int rc; |
|
|
|
dst->range.level[0].sens = src->range.level[1].sens; |
|
rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[1].cat); |
|
if (rc) |
|
goto out; |
|
|
|
dst->range.level[1].sens = src->range.level[1].sens; |
|
rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat); |
|
if (rc) |
|
ebitmap_destroy(&dst->range.level[0].cat); |
|
out: |
|
return rc; |
|
} |
|
|
|
|
|
static inline int mls_context_glblub(struct context *dst, |
|
struct context *c1, struct context *c2) |
|
{ |
|
struct mls_range *dr = &dst->range, *r1 = &c1->range, *r2 = &c2->range; |
|
int rc = 0; |
|
|
|
if (r1->level[1].sens < r2->level[0].sens || |
|
r2->level[1].sens < r1->level[0].sens) |
|
/* These ranges have no common sensitivities */ |
|
return -EINVAL; |
|
|
|
/* Take the greatest of the low */ |
|
dr->level[0].sens = max(r1->level[0].sens, r2->level[0].sens); |
|
|
|
/* Take the least of the high */ |
|
dr->level[1].sens = min(r1->level[1].sens, r2->level[1].sens); |
|
|
|
rc = ebitmap_and(&dr->level[0].cat, |
|
&r1->level[0].cat, &r2->level[0].cat); |
|
if (rc) |
|
goto out; |
|
|
|
rc = ebitmap_and(&dr->level[1].cat, |
|
&r1->level[1].cat, &r2->level[1].cat); |
|
if (rc) |
|
goto out; |
|
|
|
out: |
|
return rc; |
|
} |
|
|
|
static inline int mls_context_cmp(struct context *c1, struct context *c2) |
|
{ |
|
return ((c1->range.level[0].sens == c2->range.level[0].sens) && |
|
ebitmap_cmp(&c1->range.level[0].cat, &c2->range.level[0].cat) && |
|
(c1->range.level[1].sens == c2->range.level[1].sens) && |
|
ebitmap_cmp(&c1->range.level[1].cat, &c2->range.level[1].cat)); |
|
} |
|
|
|
static inline void mls_context_destroy(struct context *c) |
|
{ |
|
ebitmap_destroy(&c->range.level[0].cat); |
|
ebitmap_destroy(&c->range.level[1].cat); |
|
mls_context_init(c); |
|
} |
|
|
|
static inline void context_init(struct context *c) |
|
{ |
|
memset(c, 0, sizeof(*c)); |
|
} |
|
|
|
static inline int context_cpy(struct context *dst, struct context *src) |
|
{ |
|
int rc; |
|
|
|
dst->user = src->user; |
|
dst->role = src->role; |
|
dst->type = src->type; |
|
if (src->str) { |
|
dst->str = kstrdup(src->str, GFP_ATOMIC); |
|
if (!dst->str) |
|
return -ENOMEM; |
|
dst->len = src->len; |
|
} else { |
|
dst->str = NULL; |
|
dst->len = 0; |
|
} |
|
rc = mls_context_cpy(dst, src); |
|
if (rc) { |
|
kfree(dst->str); |
|
return rc; |
|
} |
|
return 0; |
|
} |
|
|
|
static inline void context_destroy(struct context *c) |
|
{ |
|
c->user = c->role = c->type = 0; |
|
kfree(c->str); |
|
c->str = NULL; |
|
c->len = 0; |
|
mls_context_destroy(c); |
|
} |
|
|
|
static inline int context_cmp(struct context *c1, struct context *c2) |
|
{ |
|
if (c1->len && c2->len) |
|
return (c1->len == c2->len && !strcmp(c1->str, c2->str)); |
|
if (c1->len || c2->len) |
|
return 0; |
|
return ((c1->user == c2->user) && |
|
(c1->role == c2->role) && |
|
(c1->type == c2->type) && |
|
mls_context_cmp(c1, c2)); |
|
} |
|
|
|
u32 context_compute_hash(const struct context *c); |
|
|
|
#endif /* _SS_CONTEXT_H_ */ |
|
|
|
|