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 |
18 | struct cgroup_cls_state { |
19 | struct cgroup_subsys_state css; |
20 | u32 classid; |
21 | }; |
22 | |
23 | struct cgroup_cls_state *task_cls_state(struct task_struct *p); |
24 | |
25 | static 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 | |
40 | static 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 | |
48 | static inline u32 __task_get_classid(struct task_struct *task) |
49 | { |
50 | return task_cls_state(p: task)->classid; |
51 | } |
52 | |
53 | static 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(skcd: &sk->sk_cgrp_data); |
74 | } |
75 | |
76 | return classid; |
77 | } |
78 | #else /* !CONFIG_CGROUP_NET_CLASSID */ |
79 | static inline void sock_update_classid(struct sock_cgroup_data *skcd) |
80 | { |
81 | } |
82 | |
83 | static 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 */ |
89 |