153 строки
3.5 KiB
C
153 строки
3.5 KiB
C
/*
|
|
* net/sched/sch_fifo.c The simplest FIFO 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: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/skbuff.h>
|
|
#include <net/pkt_sched.h>
|
|
|
|
/* 1 band FIFO pseudo-"scheduler" */
|
|
|
|
struct fifo_sched_data
|
|
{
|
|
u32 limit;
|
|
};
|
|
|
|
static int bfifo_enqueue(struct sk_buff *skb, struct Qdisc* sch)
|
|
{
|
|
struct fifo_sched_data *q = qdisc_priv(sch);
|
|
|
|
if (likely(sch->qstats.backlog + qdisc_pkt_len(skb) <= q->limit))
|
|
return qdisc_enqueue_tail(skb, sch);
|
|
|
|
return qdisc_reshape_fail(skb, sch);
|
|
}
|
|
|
|
static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc* sch)
|
|
{
|
|
struct fifo_sched_data *q = qdisc_priv(sch);
|
|
|
|
if (likely(skb_queue_len(&sch->q) < q->limit))
|
|
return qdisc_enqueue_tail(skb, sch);
|
|
|
|
return qdisc_reshape_fail(skb, sch);
|
|
}
|
|
|
|
static int fifo_init(struct Qdisc *sch, struct nlattr *opt)
|
|
{
|
|
struct fifo_sched_data *q = qdisc_priv(sch);
|
|
|
|
if (opt == NULL) {
|
|
u32 limit = qdisc_dev(sch)->tx_queue_len ? : 1;
|
|
|
|
if (sch->ops == &bfifo_qdisc_ops)
|
|
limit *= qdisc_dev(sch)->mtu;
|
|
|
|
q->limit = limit;
|
|
} else {
|
|
struct tc_fifo_qopt *ctl = nla_data(opt);
|
|
|
|
if (nla_len(opt) < sizeof(*ctl))
|
|
return -EINVAL;
|
|
|
|
q->limit = ctl->limit;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int fifo_dump(struct Qdisc *sch, struct sk_buff *skb)
|
|
{
|
|
struct fifo_sched_data *q = qdisc_priv(sch);
|
|
struct tc_fifo_qopt opt = { .limit = q->limit };
|
|
|
|
NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
|
|
return skb->len;
|
|
|
|
nla_put_failure:
|
|
return -1;
|
|
}
|
|
|
|
struct Qdisc_ops pfifo_qdisc_ops __read_mostly = {
|
|
.id = "pfifo",
|
|
.priv_size = sizeof(struct fifo_sched_data),
|
|
.enqueue = pfifo_enqueue,
|
|
.dequeue = qdisc_dequeue_head,
|
|
.requeue = qdisc_requeue,
|
|
.drop = qdisc_queue_drop,
|
|
.init = fifo_init,
|
|
.reset = qdisc_reset_queue,
|
|
.change = fifo_init,
|
|
.dump = fifo_dump,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
EXPORT_SYMBOL(pfifo_qdisc_ops);
|
|
|
|
struct Qdisc_ops bfifo_qdisc_ops __read_mostly = {
|
|
.id = "bfifo",
|
|
.priv_size = sizeof(struct fifo_sched_data),
|
|
.enqueue = bfifo_enqueue,
|
|
.dequeue = qdisc_dequeue_head,
|
|
.requeue = qdisc_requeue,
|
|
.drop = qdisc_queue_drop,
|
|
.init = fifo_init,
|
|
.reset = qdisc_reset_queue,
|
|
.change = fifo_init,
|
|
.dump = fifo_dump,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
EXPORT_SYMBOL(bfifo_qdisc_ops);
|
|
|
|
/* Pass size change message down to embedded FIFO */
|
|
int fifo_set_limit(struct Qdisc *q, unsigned int limit)
|
|
{
|
|
struct nlattr *nla;
|
|
int ret = -ENOMEM;
|
|
|
|
/* Hack to avoid sending change message to non-FIFO */
|
|
if (strncmp(q->ops->id + 1, "fifo", 4) != 0)
|
|
return 0;
|
|
|
|
nla = kmalloc(nla_attr_size(sizeof(struct tc_fifo_qopt)), GFP_KERNEL);
|
|
if (nla) {
|
|
nla->nla_type = RTM_NEWQDISC;
|
|
nla->nla_len = nla_attr_size(sizeof(struct tc_fifo_qopt));
|
|
((struct tc_fifo_qopt *)nla_data(nla))->limit = limit;
|
|
|
|
ret = q->ops->change(q, nla);
|
|
kfree(nla);
|
|
}
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(fifo_set_limit);
|
|
|
|
struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
|
|
unsigned int limit)
|
|
{
|
|
struct Qdisc *q;
|
|
int err = -ENOMEM;
|
|
|
|
q = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
|
|
ops, TC_H_MAKE(sch->handle, 1));
|
|
if (q) {
|
|
err = fifo_set_limit(q, limit);
|
|
if (err < 0) {
|
|
qdisc_destroy(q);
|
|
q = NULL;
|
|
}
|
|
}
|
|
|
|
return q ? : ERR_PTR(err);
|
|
}
|
|
EXPORT_SYMBOL(fifo_create_dflt);
|