[linux-2.6-block.git] / include / net / cls_cgroup.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * cls_cgroup.h			Control Group Classifier
 *
 * Authors:	Thomas Graf <tgraf@suug.ch>
 */

#ifndef _NET_CLS_CGROUP_H
#define _NET_CLS_CGROUP_H

#include <linux/cgroup.h>
#include <linux/hardirq.h>
#include <linux/rcupdate.h>
#include <net/sock.h>
#include <net/inet_sock.h>

#ifdef CONFIG_CGROUP_NET_CLASSID
struct cgroup_cls_state {
	struct cgroup_subsys_state css;
	u32 classid;
};

struct cgroup_cls_state *task_cls_state(struct task_struct *p);

static inline u32 task_cls_classid(struct task_struct *p)
{
	u32 classid;

	if (in_interrupt())
		return 0;

	rcu_read_lock();
	classid = container_of(task_css(p, net_cls_cgrp_id),
			       struct cgroup_cls_state, css)->classid;
	rcu_read_unlock();

	return classid;
}

static inline void sock_update_classid(struct sock_cgroup_data *skcd)
{
	u32 classid;

	classid = task_cls_classid(current);
	sock_cgroup_set_classid(skcd, classid);
}

static inline u32 task_get_classid(const struct sk_buff *skb)
{
	u32 classid = task_cls_state(current)->classid;

	/* Due to the nature of the classifier it is required to ignore all
	 * packets originating from softirq context as accessing `current'
	 * would lead to false results.
	 *
	 * This test assumes that all callers of dev_queue_xmit() explicitly
	 * disable bh. Knowing this, it is possible to detect softirq based
	 * calls by looking at the number of nested bh disable calls because
	 * softirqs always disables bh.
	 */
	if (in_serving_softirq()) {
		struct sock *sk = skb_to_full_sk(skb);

		/* If there is an sock_cgroup_classid we'll use that. */
		if (!sk || !sk_fullsock(sk))
			return 0;

		classid = sock_cgroup_classid(&sk->sk_cgrp_data);
	}

	return classid;
}
#else /* !CONFIG_CGROUP_NET_CLASSID */
static inline void sock_update_classid(struct sock_cgroup_data *skcd)
{
}

static inline u32 task_get_classid(const struct sk_buff *skb)
{
	return 0;
}
#endif /* CONFIG_CGROUP_NET_CLASSID */
#endif  /* _NET_CLS_CGROUP_H */
Commit	Line	Data
2874c5fd	1	/* SPDX-License-Identifier: GPL-2.0-or-later */
f8451725 HX	2	/*
	3	* cls_cgroup.h Control Group Classifier
	4	*
	5	* Authors: Thomas Graf <tgraf@suug.ch>
f8451725 HX	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>
fe1217c4	14	#include <net/sock.h>
2309236c	15	#include <net/inet_sock.h>
f8451725	16
fe1217c4 DB	17	#ifdef CONFIG_CGROUP_NET_CLASSID
fe1217c4 DB	18	struct cgroup_cls_state {
f8451725 HX	19	struct cgroup_subsys_state css;
	20	u32 classid;
	21	};
	22
fe1217c4	23	struct cgroup_cls_state task_cls_state(struct task_struct p);
f3419807	24
f8451725 HX	25	static inline u32 task_cls_classid(struct task_struct *p)
f8451725 HX	26	{
920750ce	27	u32 classid;
3fb5a991	28
f8451725 HX	29	if (in_interrupt())
	30	return 0;
	31
3fb5a991	32	rcu_read_lock();
073219e9	33	classid = container_of(task_css(p, net_cls_cgrp_id),
3fb5a991 LZ	34	struct cgroup_cls_state, css)->classid;
	35	rcu_read_unlock();
	36
	37	return classid;
f8451725	38	}
f8451725	39
2a56a1fe	40	static inline void sock_update_classid(struct sock_cgroup_data *skcd)
f3419807	41	{
fe1217c4	42	u32 classid;
f3419807	43
fe1217c4	44	classid = task_cls_classid(current);
2a56a1fe	45	sock_cgroup_set_classid(skcd, classid);
fe1217c4	46	}
b87a173e DB	47
	48	static inline u32 task_get_classid(const struct sk_buff *skb)
	49	{
	50	u32 classid = task_cls_state(current)->classid;
	51
	52	/* Due to the nature of the classifier it is required to ignore all
	53	* packets originating from softirq context as accessing `current'
	54	* would lead to false results.
	55	*
	56	* This test assumes that all callers of dev_queue_xmit() explicitly
	57	* disable bh. Knowing this, it is possible to detect softirq based
	58	* calls by looking at the number of nested bh disable calls because
	59	* softirqs always disables bh.
	60	*/
	61	if (in_serving_softirq()) {
2309236c KK	62	struct sock *sk = skb_to_full_sk(skb);
2309236c KK	63
2a56a1fe	64	/* If there is an sock_cgroup_classid we'll use that. */
2309236c	65	if (!sk \|\| !sk_fullsock(sk))
b87a173e DB	66	return 0;
b87a173e DB	67
2309236c	68	classid = sock_cgroup_classid(&sk->sk_cgrp_data);
b87a173e DB	69	}
	70
	71	return classid;
	72	}
fe1217c4	73	#else /* !CONFIG_CGROUP_NET_CLASSID */
2a56a1fe	74	static inline void sock_update_classid(struct sock_cgroup_data *skcd)
f8451725	75	{
f8451725	76	}
b87a173e DB	77
	78	static inline u32 task_get_classid(const struct sk_buff *skb)
	79	{
	80	return 0;
	81	}
fe1217c4	82	#endif /* CONFIG_CGROUP_NET_CLASSID */
f8451725	83	#endif /* _NET_CLS_CGROUP_H */