164 lines
4.0 KiB
C
164 lines
4.0 KiB
C
/*
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* A security context is a set of security attributes
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* associated with each subject and object controlled
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* by the security policy. Security contexts are
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* externally represented as variable-length strings
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* that can be interpreted by a user or application
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* with an understanding of the security policy.
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* Internally, the security server uses a simple
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* structure. This structure is private to the
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* security server and can be changed without affecting
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* clients of the security server.
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*
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* Author : Stephen Smalley, <sds@epoch.ncsc.mil>
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*/
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#ifndef _SS_CONTEXT_H_
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#define _SS_CONTEXT_H_
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#include "ebitmap.h"
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#include "mls_types.h"
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#include "security.h"
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/*
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* A security context consists of an authenticated user
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* identity, a role, a type and a MLS range.
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*/
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struct context {
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u32 user;
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u32 role;
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u32 type;
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u32 len; /* length of string in bytes */
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struct mls_range range;
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char *str; /* string representation if context cannot be mapped. */
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};
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static inline void mls_context_init(struct context *c)
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{
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memset(&c->range, 0, sizeof(c->range));
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}
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static inline int mls_context_cpy(struct context *dst, struct context *src)
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{
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int rc;
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dst->range.level[0].sens = src->range.level[0].sens;
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rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat);
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if (rc)
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goto out;
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dst->range.level[1].sens = src->range.level[1].sens;
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rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat);
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if (rc)
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ebitmap_destroy(&dst->range.level[0].cat);
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out:
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return rc;
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}
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/*
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* Sets both levels in the MLS range of 'dst' to the low level of 'src'.
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*/
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static inline int mls_context_cpy_low(struct context *dst, struct context *src)
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{
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int rc;
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dst->range.level[0].sens = src->range.level[0].sens;
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rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat);
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if (rc)
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goto out;
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dst->range.level[1].sens = src->range.level[0].sens;
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rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[0].cat);
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if (rc)
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ebitmap_destroy(&dst->range.level[0].cat);
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out:
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return rc;
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}
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/*
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* Sets both levels in the MLS range of 'dst' to the high level of 'src'.
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*/
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static inline int mls_context_cpy_high(struct context *dst, struct context *src)
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{
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int rc;
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dst->range.level[0].sens = src->range.level[1].sens;
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rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[1].cat);
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if (rc)
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goto out;
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dst->range.level[1].sens = src->range.level[1].sens;
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rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat);
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if (rc)
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ebitmap_destroy(&dst->range.level[0].cat);
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out:
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return rc;
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}
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static inline int mls_context_cmp(struct context *c1, struct context *c2)
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{
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return ((c1->range.level[0].sens == c2->range.level[0].sens) &&
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ebitmap_cmp(&c1->range.level[0].cat, &c2->range.level[0].cat) &&
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(c1->range.level[1].sens == c2->range.level[1].sens) &&
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ebitmap_cmp(&c1->range.level[1].cat, &c2->range.level[1].cat));
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}
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static inline void mls_context_destroy(struct context *c)
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{
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ebitmap_destroy(&c->range.level[0].cat);
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ebitmap_destroy(&c->range.level[1].cat);
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mls_context_init(c);
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}
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static inline void context_init(struct context *c)
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{
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memset(c, 0, sizeof(*c));
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}
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static inline int context_cpy(struct context *dst, struct context *src)
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{
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int rc;
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dst->user = src->user;
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dst->role = src->role;
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dst->type = src->type;
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if (src->str) {
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dst->str = kstrdup(src->str, GFP_ATOMIC);
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if (!dst->str)
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return -ENOMEM;
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dst->len = src->len;
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} else {
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dst->str = NULL;
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dst->len = 0;
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}
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rc = mls_context_cpy(dst, src);
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if (rc) {
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kfree(dst->str);
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return rc;
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}
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return 0;
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}
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static inline void context_destroy(struct context *c)
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{
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c->user = c->role = c->type = 0;
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kfree(c->str);
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c->str = NULL;
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c->len = 0;
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mls_context_destroy(c);
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}
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static inline int context_cmp(struct context *c1, struct context *c2)
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{
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if (c1->len && c2->len)
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return (c1->len == c2->len && !strcmp(c1->str, c2->str));
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if (c1->len || c2->len)
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return 0;
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return ((c1->user == c2->user) &&
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(c1->role == c2->role) &&
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(c1->type == c2->type) &&
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mls_context_cmp(c1, c2));
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}
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#endif /* _SS_CONTEXT_H_ */
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