1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Landlock LSM - Credential hooks
4  *
5  * Copyright © 2019-2020 Mickaël Salaün <mic@digikod.net>
6  * Copyright © 2019-2020 ANSSI
7  */
8 
9 #ifndef _SECURITY_LANDLOCK_CRED_H
10 #define _SECURITY_LANDLOCK_CRED_H
11 
12 #include <linux/cred.h>
13 #include <linux/init.h>
14 #include <linux/rcupdate.h>
15 
16 #include "ruleset.h"
17 #include "setup.h"
18 
19 struct landlock_cred_security {
20 	struct landlock_ruleset *domain;
21 };
22 
landlock_cred(const struct cred * cred)23 static inline struct landlock_cred_security *landlock_cred(
24 		const struct cred *cred)
25 {
26 	return cred->security + landlock_blob_sizes.lbs_cred;
27 }
28 
landlock_get_current_domain(void)29 static inline const struct landlock_ruleset *landlock_get_current_domain(void)
30 {
31 	return landlock_cred(current_cred())->domain;
32 }
33 
34 /*
35  * The call needs to come from an RCU read-side critical section.
36  */
landlock_get_task_domain(const struct task_struct * const task)37 static inline const struct landlock_ruleset *landlock_get_task_domain(
38 		const struct task_struct *const task)
39 {
40 	return landlock_cred(__task_cred(task))->domain;
41 }
42 
landlocked(const struct task_struct * const task)43 static inline bool landlocked(const struct task_struct *const task)
44 {
45 	bool has_dom;
46 
47 	if (task == current)
48 		return !!landlock_get_current_domain();
49 
50 	rcu_read_lock();
51 	has_dom = !!landlock_get_task_domain(task);
52 	rcu_read_unlock();
53 	return has_dom;
54 }
55 
56 __init void landlock_add_cred_hooks(void);
57 
58 #endif /* _SECURITY_LANDLOCK_CRED_H */
59