linux/net/sched/sch_blackhole.c
Konstantin Khlebnikov 7e85dc8cb3 net_sched: blackhole: tell upper qdisc about dropped packets
When blackhole is used on top of classful qdisc like hfsc it breaks
qlen and backlog counters because packets are disappear without notice.

In HFSC non-zero qlen while all classes are inactive triggers warning:
WARNING: ... at net/sched/sch_hfsc.c:1393 hfsc_dequeue+0xba4/0xe90 [sch_hfsc]
and schedules watchdog work endlessly.

This patch return __NET_XMIT_BYPASS in addition to NET_XMIT_SUCCESS,
this flag tells upper layer: this packet is gone and isn't queued.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-17 08:42:33 +09:00

46 lines
1.1 KiB
C

/*
* net/sched/sch_blackhole.c Black hole queue
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Authors: Thomas Graf <tgraf@suug.ch>
*
* Note: Quantum tunneling is not supported.
*/
#include <linux/init.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <net/pkt_sched.h>
static int blackhole_enqueue(struct sk_buff *skb, struct Qdisc *sch,
struct sk_buff **to_free)
{
qdisc_drop(skb, sch, to_free);
return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
}
static struct sk_buff *blackhole_dequeue(struct Qdisc *sch)
{
return NULL;
}
static struct Qdisc_ops blackhole_qdisc_ops __read_mostly = {
.id = "blackhole",
.priv_size = 0,
.enqueue = blackhole_enqueue,
.dequeue = blackhole_dequeue,
.peek = blackhole_dequeue,
.owner = THIS_MODULE,
};
static int __init blackhole_init(void)
{
return register_qdisc(&blackhole_qdisc_ops);
}
device_initcall(blackhole_init)