| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 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 | #include <net/inet_sock.h> |
| 21 | |
| 22 | #ifdef CONFIG_CGROUP_NET_CLASSID |
| 23 | struct cgroup_cls_state { |
| 24 | struct cgroup_subsys_state css; |
| 25 | u32 classid; |
| 26 | }; |
| 27 | |
| 28 | struct cgroup_cls_state *task_cls_state(struct task_struct *p); |
| 29 | |
| 30 | static inline u32 task_cls_classid(struct task_struct *p) |
| 31 | { |
| 32 | u32 classid; |
| 33 | |
| 34 | if (in_interrupt()) |
| 35 | return 0; |
| 36 | |
| 37 | rcu_read_lock(); |
| 38 | classid = container_of(task_css(p, net_cls_cgrp_id), |
| 39 | struct cgroup_cls_state, css)->classid; |
| 40 | rcu_read_unlock(); |
| 41 | |
| 42 | return classid; |
| 43 | } |
| 44 | |
| 45 | static inline void sock_update_classid(struct sock_cgroup_data *skcd) |
| 46 | { |
| 47 | u32 classid; |
| 48 | |
| 49 | classid = task_cls_classid(current); |
| 50 | sock_cgroup_set_classid(skcd, classid); |
| 51 | } |
| 52 | |
| 53 | static 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 | 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 */ |
| 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 */ |