xref: /linux/include/linux/kobject_ns.h (revision 7c6c4ed80b874f721bc7c2c937e098c56e37d2f0)
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 ns_common;
20 struct sock;
21 struct kobject;
22 
23 /*
24  * Namespace types which are used to tag kobjects and sysfs entries.
25  * Network namespace will likely be the first.
26  */
27 enum kobj_ns_type {
28 	KOBJ_NS_TYPE_NONE = 0,
29 	KOBJ_NS_TYPE_NET,
30 	KOBJ_NS_TYPES
31 };
32 
33 /*
34  * Callbacks so sysfs can determine namespaces
35  *   @grab_current_ns: return a new reference to calling task's namespace
36  *   @netlink_ns: return namespace to which a sock belongs (right?)
37  *   @initial_ns: return the initial namespace (i.e. init_net_ns)
38  *   @drop_ns: drops a reference to namespace
39  */
40 struct kobj_ns_type_operations {
41 	enum kobj_ns_type type;
42 	bool (*current_may_mount)(void);
43 	struct ns_common *(*grab_current_ns)(void);
44 	const struct ns_common *(*netlink_ns)(struct sock *sk);
45 	const struct ns_common *(*initial_ns)(void);
46 	void (*drop_ns)(struct ns_common *);
47 };
48 
49 int kobj_ns_type_register(const struct kobj_ns_type_operations *ops);
50 int kobj_ns_type_registered(enum kobj_ns_type type);
51 const struct kobj_ns_type_operations *kobj_child_ns_ops(const struct kobject *parent);
52 const struct kobj_ns_type_operations *kobj_ns_ops(const struct kobject *kobj);
53 
54 bool kobj_ns_current_may_mount(enum kobj_ns_type type);
55 struct ns_common *kobj_ns_grab_current(enum kobj_ns_type type);
56 void kobj_ns_drop(enum kobj_ns_type type, struct ns_common *ns);
57 
58 #endif /* _LINUX_KOBJECT_NS_H */
59