/* * cls_cgroup.h Control Group Classifier * * Authors: Thomas Graf <tgraf@suug.ch> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or (at your option) * any later version. * */ #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 */