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 */ 89