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 * 147efbb60bSStephen Smalley * Author : Stephen Smalley, <sds@tycho.nsa.gov> 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. */ 3466f8e2f0SJeff Vander Stoep u32 hash; /* a hash of the string representation */ 351da177e4SLinus Torvalds }; 361da177e4SLinus Torvalds 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 421da177e4SLinus Torvalds static inline int mls_context_cpy(struct context *dst, struct context *src) 431da177e4SLinus Torvalds { 441da177e4SLinus Torvalds int rc; 451da177e4SLinus Torvalds 461da177e4SLinus Torvalds dst->range.level[0].sens = src->range.level[0].sens; 471da177e4SLinus Torvalds rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat); 481da177e4SLinus Torvalds if (rc) 491da177e4SLinus Torvalds goto out; 501da177e4SLinus Torvalds 511da177e4SLinus Torvalds dst->range.level[1].sens = src->range.level[1].sens; 521da177e4SLinus Torvalds rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat); 531da177e4SLinus Torvalds if (rc) 541da177e4SLinus Torvalds ebitmap_destroy(&dst->range.level[0].cat); 551da177e4SLinus Torvalds out: 561da177e4SLinus Torvalds return rc; 571da177e4SLinus Torvalds } 581da177e4SLinus Torvalds 590efc61eaSVenkat Yekkirala /* 600efc61eaSVenkat Yekkirala * Sets both levels in the MLS range of 'dst' to the low level of 'src'. 610efc61eaSVenkat Yekkirala */ 620efc61eaSVenkat Yekkirala static inline int mls_context_cpy_low(struct context *dst, struct context *src) 630efc61eaSVenkat Yekkirala { 640efc61eaSVenkat Yekkirala int rc; 650efc61eaSVenkat Yekkirala 660efc61eaSVenkat Yekkirala dst->range.level[0].sens = src->range.level[0].sens; 670efc61eaSVenkat Yekkirala rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat); 680efc61eaSVenkat Yekkirala if (rc) 690efc61eaSVenkat Yekkirala goto out; 700efc61eaSVenkat Yekkirala 710efc61eaSVenkat Yekkirala dst->range.level[1].sens = src->range.level[0].sens; 720efc61eaSVenkat Yekkirala rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[0].cat); 730efc61eaSVenkat Yekkirala if (rc) 740efc61eaSVenkat Yekkirala ebitmap_destroy(&dst->range.level[0].cat); 750efc61eaSVenkat Yekkirala out: 760efc61eaSVenkat Yekkirala return rc; 770efc61eaSVenkat Yekkirala } 780efc61eaSVenkat Yekkirala 79aa893269SEric Paris /* 80aa893269SEric Paris * Sets both levels in the MLS range of 'dst' to the high level of 'src'. 81aa893269SEric Paris */ 82aa893269SEric Paris static inline int mls_context_cpy_high(struct context *dst, struct context *src) 83aa893269SEric Paris { 84aa893269SEric Paris int rc; 85aa893269SEric Paris 86aa893269SEric Paris dst->range.level[0].sens = src->range.level[1].sens; 87aa893269SEric Paris rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[1].cat); 88aa893269SEric Paris if (rc) 89aa893269SEric Paris goto out; 90aa893269SEric Paris 91aa893269SEric Paris dst->range.level[1].sens = src->range.level[1].sens; 92aa893269SEric Paris rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat); 93aa893269SEric Paris if (rc) 94aa893269SEric Paris ebitmap_destroy(&dst->range.level[0].cat); 95aa893269SEric Paris out: 96aa893269SEric Paris return rc; 97aa893269SEric Paris } 98aa893269SEric Paris 9942345b68SJoshua Brindle 10042345b68SJoshua Brindle static inline int mls_context_glblub(struct context *dst, 10142345b68SJoshua Brindle struct context *c1, struct context *c2) 10242345b68SJoshua Brindle { 10342345b68SJoshua Brindle struct mls_range *dr = &dst->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 1311da177e4SLinus Torvalds static inline int mls_context_cmp(struct context *c1, 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 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 1461da177e4SLinus Torvalds static inline void context_init(struct context *c) 1471da177e4SLinus Torvalds { 1481da177e4SLinus Torvalds memset(c, 0, sizeof(*c)); 1491da177e4SLinus Torvalds } 1501da177e4SLinus Torvalds 1511da177e4SLinus Torvalds static inline int context_cpy(struct context *dst, 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); 17012b29f34SStephen Smalley return rc; 17112b29f34SStephen Smalley } 17266f8e2f0SJeff Vander Stoep dst->hash = src->hash; 17312b29f34SStephen Smalley return 0; 1741da177e4SLinus Torvalds } 1751da177e4SLinus Torvalds 1761da177e4SLinus Torvalds static inline void context_destroy(struct context *c) 1771da177e4SLinus Torvalds { 17866f8e2f0SJeff Vander Stoep c->user = c->role = c->type = c->hash = 0; 17912b29f34SStephen Smalley kfree(c->str); 18012b29f34SStephen Smalley c->str = NULL; 18112b29f34SStephen Smalley c->len = 0; 1821da177e4SLinus Torvalds mls_context_destroy(c); 1831da177e4SLinus Torvalds } 1841da177e4SLinus Torvalds 1851da177e4SLinus Torvalds static inline int context_cmp(struct context *c1, struct context *c2) 1861da177e4SLinus Torvalds { 18766f8e2f0SJeff Vander Stoep if (c1->hash && c2->hash && (c1->hash != c2->hash)) 18866f8e2f0SJeff Vander Stoep return 0; 18912b29f34SStephen Smalley if (c1->len && c2->len) 19012b29f34SStephen Smalley return (c1->len == c2->len && !strcmp(c1->str, c2->str)); 19112b29f34SStephen Smalley if (c1->len || c2->len) 19212b29f34SStephen Smalley return 0; 1931da177e4SLinus Torvalds return ((c1->user == c2->user) && 1941da177e4SLinus Torvalds (c1->role == c2->role) && 1951da177e4SLinus Torvalds (c1->type == c2->type) && 1961da177e4SLinus Torvalds mls_context_cmp(c1, c2)); 1971da177e4SLinus Torvalds } 1981da177e4SLinus Torvalds 199*50077289SOndrej Mosnacek u32 context_compute_hash(const struct context *c); 200*50077289SOndrej Mosnacek 201*50077289SOndrej Mosnacek static inline void context_add_hash(struct context *context) 20266f8e2f0SJeff Vander Stoep { 203*50077289SOndrej Mosnacek context->hash = context_compute_hash(context); 20466f8e2f0SJeff Vander Stoep } 20566f8e2f0SJeff Vander Stoep 2061da177e4SLinus Torvalds #endif /* _SS_CONTEXT_H_ */ 2071da177e4SLinus Torvalds 208