sch_choke: add choke_skb_cb
Better document choke skb->cb[] use, like we did in netem and sfb
This adds a compile time check to make sure we dont exhaust skb->cb[]
space.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Stephen Hemminger <shemminger@vyatta.com>
CC: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_choke.c b/net/sched/sch_choke.c
index ee1e209..06afbae 100644
--- a/net/sched/sch_choke.c
+++ b/net/sched/sch_choke.c
@@ -219,14 +219,25 @@
return *ports1 == *ports2;
}
+struct choke_skb_cb {
+ u16 classid;
+};
+
+static inline struct choke_skb_cb *choke_skb_cb(const struct sk_buff *skb)
+{
+ BUILD_BUG_ON(sizeof(skb->cb) <
+ sizeof(struct qdisc_skb_cb) + sizeof(struct choke_skb_cb));
+ return (struct choke_skb_cb *)qdisc_skb_cb(skb)->data;
+}
+
static inline void choke_set_classid(struct sk_buff *skb, u16 classid)
{
- *(unsigned int *)(qdisc_skb_cb(skb)->data) = classid;
+ choke_skb_cb(skb)->classid = classid;
}
static u16 choke_get_classid(const struct sk_buff *skb)
{
- return *(unsigned int *)(qdisc_skb_cb(skb)->data);
+ return choke_skb_cb(skb)->classid;
}
/*