tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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#include <net/sock.h>
20
21#ifdef CONFIG_CGROUP_NET_CLASSID
22struct cgroup_cls_state {
23 struct cgroup_subsys_state css;
24 u32 classid;
25};
26
27struct cgroup_cls_state *task_cls_state(struct task_struct *p);
28
29static inline u32 task_cls_classid(struct task_struct *p)
30{
31 u32 classid;
32
33 if (in_interrupt())
34 return 0;
35
36 rcu_read_lock();
37 classid = container_of(task_css(p, net_cls_cgrp_id),
38 struct cgroup_cls_state, css)->classid;
39 rcu_read_unlock();
40
41 return classid;
42}
43
44static inline void sock_update_classid(struct sock *sk)
45{
46 u32 classid;
47
48 classid = task_cls_classid(current);
49 if (classid != sk->sk_classid)
50 sk->sk_classid = classid;
51}
52
53static inline u32 task_get_classid(const struct sk_buff *skb)
54{
55 u32 classid = task_cls_state(current)->classid;
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 /* If there is an sk_classid we'll use that. */
68 if (!skb->sk)
69 return 0;
70
71 classid = skb->sk->sk_classid;
72 }
73
74 return classid;
75}
76#else /* !CONFIG_CGROUP_NET_CLASSID */
77static inline void sock_update_classid(struct sock *sk)
78{
79}
80
81static inline u32 task_get_classid(const struct sk_buff *skb)
82{
83 return 0;
84}
85#endif /* CONFIG_CGROUP_NET_CLASSID */
86#endif /* _NET_CLS_CGROUP_H */