pkt_sched: sch_generic: Add generic qdisc->ops->peek() implementation.

[deliverable/linux.git] / net / sched / sch_api.c

diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index b16ad2972c6b527dc2013a5dfb4108ad35ef8197..e5646614e88d83733acf9ccd105885358fe0a12e 100644 (file)
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -102,6 +102,10 @@ static int tclass_notify(struct sk_buff *oskb, struct nlmsghdr *n,
    requeues once dequeued packet. It is used for non-standard or
    just buggy devices, which can defer output even if netif_queue_stopped()=0.
 
+   ---peek
+
+   like dequeue but without removing a packet from the queue
+
    ---reset
 
    returns qdisc to initial state: purge all buffers, clear all
@@ -149,6 +153,14 @@ int register_qdisc(struct Qdisc_ops *qops)
                qops->enqueue = noop_qdisc_ops.enqueue;
        if (qops->requeue == NULL)
                qops->requeue = noop_qdisc_ops.requeue;
+       if (qops->peek == NULL) {
+               if (qops->dequeue == NULL) {
+                       qops->peek = noop_qdisc_ops.peek;
+               } else {
+                       rc = -EINVAL;
+                       goto out;
+               }
+       }
        if (qops->dequeue == NULL)
                qops->dequeue = noop_qdisc_ops.dequeue;