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 <dan...@iogearbox.net>
Cc: Thomas Graf <tg...@suug.ch>
---
include/net/cls_cgroup.h | 29 +++++++++++++++++++++++++++++
net/sched/cls_cgroup.c | 23 ++---------------------
2 files changed, 31 insertions(+), 21 deletions(-)
diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h
index c15d394..e85a22d 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 */
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index ea611b21..4c85bd3 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -30,35 +30,16 @@ static int cls_cgroup_classify(struct sk_buff *skb, const
struct tcf_proto *tp,
struct tcf_result *res)
{
struct cls_cgroup_head *head = rcu_dereference_bh(tp->root);
- u32 classid;
-
- 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() explicitely
- * 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 -1;
- classid = skb->sk->sk_classid;
- }
+ u32 classid = task_get_classid(skb);
if (!classid)
return -1;
-
if (!tcf_em_tree_match(skb, &head->ematches, NULL))
return -1;
res->classid = classid;
res->class = 0;
+
return tcf_exts_exec(skb, &head->exts, res);
}
--
1.9.3
--
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