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/* 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(struct task_struct *task)
{
return task_cls_state(task)->classid;
}
static inline u32 task_get_classid(const struct sk_buff *skb)
{
u32 classid = __task_get_classid(current);
/* 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 */