diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2015-07-15 14:21:41 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-07-20 12:41:30 -0700 |
| commit | b87a173e25d6bf5c26f13d329cdddf57dbd4061a (patch) | |
| tree | ed2f43c4b6058bf7ca91676afc320757fe277a15 /include | |
| parent | d9382bda4ef97d73c77ecaed7a8d5df20da8b8dd (diff) | |
cls_cgroup: factor out classid retrieval
Split out retrieving the cgroups net_cls classid retrieval into its
own function, so that it can be reused later on from other parts of
the traffic control subsystem. If there's no skb->sk, then the small
helper returns 0 as well, which in cls_cgroup terms means 'could not
classify'.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/cls_cgroup.h | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h index c15d39456e14..ccd6d8bffa4d 100644 --- a/include/net/cls_cgroup.h +++ b/include/net/cls_cgroup.h @@ -49,9 +49,38 @@ static inline void sock_update_classid(struct sock *sk) if (classid != sk->sk_classid) sk->sk_classid = 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()) { + /* If there is an sk_classid we'll use that. */ + if (!skb->sk) + return 0; + + classid = skb->sk->sk_classid; + } + + return classid; +} #else /* !CONFIG_CGROUP_NET_CLASSID */ static inline void sock_update_classid(struct sock *sk) { } + +static inline u32 task_get_classid(const struct sk_buff *skb) +{ + return 0; +} #endif /* CONFIG_CGROUP_NET_CLASSID */ #endif /* _NET_CLS_CGROUP_H */ |