1 // SPDX-License-Identifier: GPL-2.0
2 /* Kernel object name space definitions
3  *
4  * Copyright (c) 2002-2003 Patrick Mochel
5  * Copyright (c) 2002-2003 Open Source Development Labs
6  * Copyright (c) 2006-2008 Greg Kroah-Hartman <greg@kroah.com>
7  * Copyright (c) 2006-2008 Novell Inc.
8  *
9  * Split from kobject.h by David Howells (dhowells@redhat.com)
10  *
11  * Please read Documentation/core-api/kobject.rst before using the kobject
12  * interface, ESPECIALLY the parts about reference counts and object
13  * destructors.
14  */
15 
16 #ifndef _LINUX_KOBJECT_NS_H
17 #define _LINUX_KOBJECT_NS_H
18 
19 struct sock;
20 struct kobject;
21 
22 /*
23  * Namespace types which are used to tag kobjects and sysfs entries.
24  * Network namespace will likely be the first.
25  */
26 enum kobj_ns_type {
27 	KOBJ_NS_TYPE_NONE = 0,
28 	KOBJ_NS_TYPE_NET,
29 	KOBJ_NS_TYPES
30 };
31 
32 /*
33  * Callbacks so sysfs can determine namespaces
34  *   @grab_current_ns: return a new reference to calling task's namespace
35  *   @netlink_ns: return namespace to which a sock belongs (right?)
36  *   @initial_ns: return the initial namespace (i.e. init_net_ns)
37  *   @drop_ns: drops a reference to namespace
38  */
39 struct kobj_ns_type_operations {
40 	enum kobj_ns_type type;
41 	bool (*current_may_mount)(void);
42 	void *(*grab_current_ns)(void);
43 	const void *(*netlink_ns)(struct sock *sk);
44 	const void *(*initial_ns)(void);
45 	void (*drop_ns)(void *);
46 };
47 
48 int kobj_ns_type_register(const struct kobj_ns_type_operations *ops);
49 int kobj_ns_type_registered(enum kobj_ns_type type);
50 const struct kobj_ns_type_operations *kobj_child_ns_ops(const struct kobject *parent);
51 const struct kobj_ns_type_operations *kobj_ns_ops(const struct kobject *kobj);
52 
53 bool kobj_ns_current_may_mount(enum kobj_ns_type type);
54 void *kobj_ns_grab_current(enum kobj_ns_type type);
55 const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk);
56 const void *kobj_ns_initial(enum kobj_ns_type type);
57 void kobj_ns_drop(enum kobj_ns_type type, void *ns);
58 
59 #endif /* _LINUX_KOBJECT_NS_H */
60