Commit 9972b25d authored by Thomas Graf's avatar Thomas Graf Committed by David S. Miller
Browse files

[PKT_SCHED]: Generic queue management interface for qdiscs using internal skb queues 



Implements an interface to be used by leaf qdiscs maintaining an internal
skb queue. The interface maintains a backlog in bytes additionaly
to the skb_queue_len() maintained by the queue itself. Relevant statistics
get incremented automatically. Every function comes in two variants, one
assuming Qdisc->q is used as queue and the second taking a sk_buff_head
as argument. Be aware that, if you use multiple queues, you still have to
maintain the Qdisc->q.qlen counter yourself.

Signed-off-by: default avatarThomas Graf <tgraf@suug.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1e061ab2

include/net/sch_generic.h

+122 −0
Original line number Diff line number Diff line
@@ -172,4 +172,126 @@ tcf_destroy(struct tcf_proto *tp) 
	kfree(tp);

}



static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch,

				       struct sk_buff_head *list)

{

	__skb_queue_tail(list, skb);

	sch->qstats.backlog += skb->len;

	sch->bstats.bytes += skb->len;

	sch->bstats.packets++;



	return NET_XMIT_SUCCESS;

}



static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)

{

	return __qdisc_enqueue_tail(skb, sch, &sch->q);

}



static inline struct sk_buff *__qdisc_dequeue_head(struct Qdisc *sch,

						   struct sk_buff_head *list)

{

	struct sk_buff *skb = __skb_dequeue(list);



	if (likely(skb != NULL))

		sch->qstats.backlog -= skb->len;



	return skb;

}



static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)

{

	return __qdisc_dequeue_head(sch, &sch->q);

}



static inline struct sk_buff *__qdisc_dequeue_tail(struct Qdisc *sch,

						   struct sk_buff_head *list)

{

	struct sk_buff *skb = __skb_dequeue_tail(list);



	if (likely(skb != NULL))

		sch->qstats.backlog -= skb->len;



	return skb;

}



static inline struct sk_buff *qdisc_dequeue_tail(struct Qdisc *sch)

{

	return __qdisc_dequeue_tail(sch, &sch->q);

}



static inline int __qdisc_requeue(struct sk_buff *skb, struct Qdisc *sch,

				  struct sk_buff_head *list)

{

	__skb_queue_head(list, skb);

	sch->qstats.backlog += skb->len;

	sch->qstats.requeues++;



	return NET_XMIT_SUCCESS;

}



static inline int qdisc_requeue(struct sk_buff *skb, struct Qdisc *sch)

{

	return __qdisc_requeue(skb, sch, &sch->q);

}



static inline void __qdisc_reset_queue(struct Qdisc *sch,

				       struct sk_buff_head *list)

{

	/*

	 * We do not know the backlog in bytes of this list, it

	 * is up to the caller to correct it

	 */

	skb_queue_purge(list);

}



static inline void qdisc_reset_queue(struct Qdisc *sch)

{

	__qdisc_reset_queue(sch, &sch->q);

	sch->qstats.backlog = 0;

}



static inline unsigned int __qdisc_queue_drop(struct Qdisc *sch,

					      struct sk_buff_head *list)

{

	struct sk_buff *skb = __qdisc_dequeue_tail(sch, list);



	if (likely(skb != NULL)) {

		unsigned int len = skb->len;

		kfree_skb(skb);

		return len;

	}



	return 0;

}



static inline unsigned int qdisc_queue_drop(struct Qdisc *sch)

{

	return __qdisc_queue_drop(sch, &sch->q);

}



static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)

{

	kfree_skb(skb);

	sch->qstats.drops++;



	return NET_XMIT_DROP;

}



static inline int qdisc_reshape_fail(struct sk_buff *skb, struct Qdisc *sch)

{

	sch->qstats.drops++;



#ifdef CONFIG_NET_CLS_POLICE

	if (sch->reshape_fail == NULL || sch->reshape_fail(skb, sch))

		goto drop;



	return NET_XMIT_SUCCESS;



drop:

#endif

	kfree_skb(skb);

	return NET_XMIT_DROP;

}



#endif

CRA Git | Maintained and supported by SUSTech CRA and CCSE