1/*
 2 * cls_cgroup.h			Control Group Classifier
 3 *
 4 * Authors:	Thomas Graf <tgraf@suug.ch>
 5 *
 6 * This program is free software; you can redistribute it and/or modify it
 7 * under the terms of the GNU General Public License as published by the Free
 8 * Software Foundation; either version 2 of the License, or (at your option)
 9 * any later version.
10 *
11 */
12
13#ifndef _NET_CLS_CGROUP_H
14#define _NET_CLS_CGROUP_H
15
16#include <linux/cgroup.h>
17#include <linux/hardirq.h>
18#include <linux/rcupdate.h>
 
 
19
20#ifdef CONFIG_CGROUPS
21struct cgroup_cls_state
22{
23	struct cgroup_subsys_state css;
24	u32 classid;
25};
26
27#ifdef CONFIG_NET_CLS_CGROUP
 
28static inline u32 task_cls_classid(struct task_struct *p)
29{
30	int classid;
31
32	if (in_interrupt())
33		return 0;
34
35	rcu_read_lock();
36	classid = container_of(task_subsys_state(p, net_cls_subsys_id),
37			       struct cgroup_cls_state, css)->classid;
38	rcu_read_unlock();
39
40	return classid;
41}
42#else
43extern int net_cls_subsys_id;
44
45static inline u32 task_cls_classid(struct task_struct *p)
46{
47	int id;
48	u32 classid = 0;
49
50	if (in_interrupt())
51		return 0;
 
52
53	rcu_read_lock();
54	id = rcu_dereference_index_check(net_cls_subsys_id,
55					 rcu_read_lock_held());
56	if (id >= 0)
57		classid = container_of(task_subsys_state(p, id),
58				       struct cgroup_cls_state, css)->classid;
59	rcu_read_unlock();
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
60
61	return classid;
62}
63#endif
64#else
65static inline u32 task_cls_classid(struct task_struct *p)
 
 
 
66{
67	return 0;
68}
69#endif
70#endif  /* _NET_CLS_CGROUP_H */

 1/* SPDX-License-Identifier: GPL-2.0-or-later */
 2/*
 3 * cls_cgroup.h			Control Group Classifier
 4 *
 5 * Authors:	Thomas Graf <tgraf@suug.ch>
 
 
 
 
 
 
 6 */
 7
 8#ifndef _NET_CLS_CGROUP_H
 9#define _NET_CLS_CGROUP_H
10
11#include <linux/cgroup.h>
12#include <linux/hardirq.h>
13#include <linux/rcupdate.h>
14#include <net/sock.h>
15#include <net/inet_sock.h>
16
17#ifdef CONFIG_CGROUP_NET_CLASSID
18struct cgroup_cls_state {
 
19	struct cgroup_subsys_state css;
20	u32 classid;
21};
22
23struct cgroup_cls_state *task_cls_state(struct task_struct *p);
24
25static inline u32 task_cls_classid(struct task_struct *p)
26{
27	u32 classid;
28
29	if (in_interrupt())
30		return 0;
31
32	rcu_read_lock();
33	classid = container_of(task_css(p, net_cls_cgrp_id),
34			       struct cgroup_cls_state, css)->classid;
35	rcu_read_unlock();
36
37	return classid;
38}
 
 
39
40static inline void sock_update_classid(struct sock_cgroup_data *skcd)
41{
42	u32 classid;
 
43
44	classid = task_cls_classid(current);
45	sock_cgroup_set_classid(skcd, classid);
46}
47
48static inline u32 __task_get_classid(struct task_struct *task)
49{
50	return task_cls_state(task)->classid;
51}
52
53static inline u32 task_get_classid(const struct sk_buff *skb)
54{
55	u32 classid = __task_get_classid(current);
56
57	/* Due to the nature of the classifier it is required to ignore all
58	 * packets originating from softirq context as accessing `current'
59	 * would lead to false results.
60	 *
61	 * This test assumes that all callers of dev_queue_xmit() explicitly
62	 * disable bh. Knowing this, it is possible to detect softirq based
63	 * calls by looking at the number of nested bh disable calls because
64	 * softirqs always disables bh.
65	 */
66	if (in_serving_softirq()) {
67		struct sock *sk = skb_to_full_sk(skb);
68
69		/* If there is an sock_cgroup_classid we'll use that. */
70		if (!sk || !sk_fullsock(sk))
71			return 0;
72
73		classid = sock_cgroup_classid(&sk->sk_cgrp_data);
74	}
75
76	return classid;
77}
78#else /* !CONFIG_CGROUP_NET_CLASSID */
79static inline void sock_update_classid(struct sock_cgroup_data *skcd)
80{
81}
82
83static inline u32 task_get_classid(const struct sk_buff *skb)
84{
85	return 0;
86}
87#endif /* CONFIG_CGROUP_NET_CLASSID */
88#endif  /* _NET_CLS_CGROUP_H */