xref: /linux/security/safesetid/lsm.h (revision 762f99f4f3cb41a775b5157dd761217beba65873)
1aeca4e2cSMicah Morton /* SPDX-License-Identifier: GPL-2.0 */
2aeca4e2cSMicah Morton /*
3aeca4e2cSMicah Morton  * SafeSetID Linux Security Module
4aeca4e2cSMicah Morton  *
5aeca4e2cSMicah Morton  * Author: Micah Morton <mortonm@chromium.org>
6aeca4e2cSMicah Morton  *
7aeca4e2cSMicah Morton  * Copyright (C) 2018 The Chromium OS Authors.
8aeca4e2cSMicah Morton  *
9aeca4e2cSMicah Morton  * This program is free software; you can redistribute it and/or modify
10aeca4e2cSMicah Morton  * it under the terms of the GNU General Public License version 2, as
11aeca4e2cSMicah Morton  * published by the Free Software Foundation.
12aeca4e2cSMicah Morton  *
13aeca4e2cSMicah Morton  */
14aeca4e2cSMicah Morton #ifndef _SAFESETID_H
15aeca4e2cSMicah Morton #define _SAFESETID_H
16aeca4e2cSMicah Morton 
17aeca4e2cSMicah Morton #include <linux/types.h>
181cd02a27SJann Horn #include <linux/uidgid.h>
191cd02a27SJann Horn #include <linux/hashtable.h>
20aeca4e2cSMicah Morton 
21aeca4e2cSMicah Morton /* Flag indicating whether initialization completed */
22*1b8b7192SAustin Kim extern int safesetid_initialized __initdata;
23aeca4e2cSMicah Morton 
241cd02a27SJann Horn enum sid_policy_type {
251cd02a27SJann Horn 	SIDPOL_DEFAULT, /* source ID is unaffected by policy */
261cd02a27SJann Horn 	SIDPOL_CONSTRAINED, /* source ID is affected by policy */
271cd02a27SJann Horn 	SIDPOL_ALLOWED /* target ID explicitly allowed */
281cd02a27SJann Horn };
291cd02a27SJann Horn 
305294bac9SThomas Cedeno typedef union {
315294bac9SThomas Cedeno 	kuid_t uid;
325294bac9SThomas Cedeno 	kgid_t gid;
335294bac9SThomas Cedeno } kid_t;
345294bac9SThomas Cedeno 
355294bac9SThomas Cedeno enum setid_type {
365294bac9SThomas Cedeno 	UID,
375294bac9SThomas Cedeno 	GID
385294bac9SThomas Cedeno };
395294bac9SThomas Cedeno 
401cd02a27SJann Horn /*
415294bac9SThomas Cedeno  * Hash table entry to store safesetid policy signifying that 'src_id'
425294bac9SThomas Cedeno  * can set*id to 'dst_id'.
431cd02a27SJann Horn  */
445294bac9SThomas Cedeno struct setid_rule {
451cd02a27SJann Horn 	struct hlist_node next;
465294bac9SThomas Cedeno 	kid_t src_id;
475294bac9SThomas Cedeno 	kid_t dst_id;
485294bac9SThomas Cedeno 
495294bac9SThomas Cedeno 	/* Flag to signal if rule is for UID's or GID's */
505294bac9SThomas Cedeno 	enum setid_type type;
511cd02a27SJann Horn };
521cd02a27SJann Horn 
5303638e62SJann Horn #define SETID_HASH_BITS 8 /* 256 buckets in hash table */
54aeca4e2cSMicah Morton 
555294bac9SThomas Cedeno /* Extension of INVALID_UID/INVALID_GID for kid_t type */
565294bac9SThomas Cedeno #define INVALID_ID (kid_t){.uid = INVALID_UID}
575294bac9SThomas Cedeno 
585294bac9SThomas Cedeno struct setid_ruleset {
5903638e62SJann Horn 	DECLARE_HASHTABLE(rules, SETID_HASH_BITS);
60fbd9acb2SJann Horn 	char *policy_str;
6103638e62SJann Horn 	struct rcu_head rcu;
625294bac9SThomas Cedeno 
635294bac9SThomas Cedeno 	//Flag to signal if ruleset is for UID's or GID's
645294bac9SThomas Cedeno 	enum setid_type type;
6503638e62SJann Horn };
6603638e62SJann Horn 
675294bac9SThomas Cedeno enum sid_policy_type _setid_policy_lookup(struct setid_ruleset *policy,
685294bac9SThomas Cedeno 		kid_t src, kid_t dst);
6903638e62SJann Horn 
705294bac9SThomas Cedeno extern struct setid_ruleset __rcu *safesetid_setuid_rules;
715294bac9SThomas Cedeno extern struct setid_ruleset __rcu *safesetid_setgid_rules;
72aeca4e2cSMicah Morton 
73aeca4e2cSMicah Morton #endif /* _SAFESETID_H */
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