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/*
* net/sched/sch_prio.c Simple 3-band priority "scheduler".
*
* 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>
* Fixes: 19990609: J Hadi Salim <hadi@nortelnetworks.com>:
* Init -- EINVAL when opt undefined
*/
#include <linux/config.h>
#include <linux/module.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/if_ether.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/notifier.h>
#include <net/ip.h>
#include <net/route.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/pkt_sched.h>
struct prio_sched_data
{
int bands;
struct tcf_proto *filter_list;
u8 prio2band[TC_PRIO_MAX+1];
struct Qdisc *queues[TCQ_PRIO_BANDS];
};
static __inline__ unsigned prio_classify(struct sk_buff *skb, struct Qdisc *sch)
{
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
struct tcf_result res;
u32 band;
band = skb->priority;
if (TC_H_MAJ(skb->priority) != sch->handle) {
if (!q->filter_list || tc_classify(skb, q->filter_list, &res)) {
if (TC_H_MAJ(band))
band = 0;
return q->prio2band[band&TC_PRIO_MAX];
}
band = res.classid;
}
band = TC_H_MIN(band) - 1;
return band < q->bands ? band : q->prio2band[0];
}
static int
prio_enqueue(struct sk_buff *skb, struct Qdisc* sch)
{
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
struct Qdisc *qdisc;
int ret;
qdisc = q->queues[prio_classify(skb, sch)];
if ((ret = qdisc->enqueue(skb, qdisc)) == 0) {
sch->stats.bytes += skb->len;
sch->stats.packets++;
sch->q.qlen++;
return 0;
}
sch->stats.drops++;
return ret;
}
static int
prio_requeue(struct sk_buff *skb, struct Qdisc* sch)
{
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
struct Qdisc *qdisc;
int ret;
qdisc = q->queues[prio_classify(skb, sch)];
if ((ret = qdisc->ops->requeue(skb, qdisc)) == 0) {
sch->q.qlen++;
return 0;
}
sch->stats.drops++;
return ret;
}
static struct sk_buff *
prio_dequeue(struct Qdisc* sch)
{
struct sk_buff *skb;
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
int prio;
struct Qdisc *qdisc;
for (prio = 0; prio < q->bands; prio++) {
qdisc = q->queues[prio];
skb = qdisc->dequeue(qdisc);
if (skb) {
sch->q.qlen--;
return skb;
}
}
return NULL;
}
static int
prio_drop(struct Qdisc* sch)
{
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
int prio;
struct Qdisc *qdisc;
for (prio = q->bands-1; prio >= 0; prio--) {
qdisc = q->queues[prio];
if (qdisc->ops->drop(qdisc)) {
sch->q.qlen--;
return 1;
}
}
return 0;
}
static void
prio_reset(struct Qdisc* sch)
{
int prio;
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
for (prio=0; prio<q->bands; prio++)
qdisc_reset(q->queues[prio]);
sch->q.qlen = 0;
}
static void
prio_destroy(struct Qdisc* sch)
{
int prio;
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
for (prio=0; prio<q->bands; prio++) {
qdisc_destroy(q->queues[prio]);
q->queues[prio] = &noop_qdisc;
}
MOD_DEC_USE_COUNT;
}
static int prio_tune(struct Qdisc *sch, struct rtattr *opt)
{
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
struct tc_prio_qopt *qopt = RTA_DATA(opt);
int i;
if (opt->rta_len < RTA_LENGTH(sizeof(*qopt)))
return -EINVAL;
if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
return -EINVAL;
for (i=0; i<=TC_PRIO_MAX; i++) {
if (qopt->priomap[i] >= qopt->bands)
return -EINVAL;
}
sch_tree_lock(sch);
q->bands = qopt->bands;
memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
for (i=q->bands; i<TCQ_PRIO_BANDS; i++) {
struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc);
if (child != &noop_qdisc)
qdisc_destroy(child);
}
sch_tree_unlock(sch);
for (i=0; i<=TC_PRIO_MAX; i++) {
int band = q->prio2band[i];
if (q->queues[band] == &noop_qdisc) {
struct Qdisc *child;
child = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
if (child) {
sch_tree_lock(sch);
child = xchg(&q->queues[band], child);
if (child != &noop_qdisc)
qdisc_destroy(child);
sch_tree_unlock(sch);
}
}
}
return 0;
}
static int prio_init(struct Qdisc *sch, struct rtattr *opt)
{
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
int i;
for (i=0; i<TCQ_PRIO_BANDS; i++)
q->queues[i] = &noop_qdisc;
if (opt == NULL) {
return -EINVAL;
} else {
int err;
if ((err= prio_tune(sch, opt)) != 0)
return err;
}
MOD_INC_USE_COUNT;
return 0;
}
static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
{
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
unsigned char *b = skb->tail;
struct tc_prio_qopt opt;
opt.bands = q->bands;
memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX+1);
RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
return skb->len;
rtattr_failure:
skb_trim(skb, b - skb->data);
return -1;
}
static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
struct Qdisc **old)
{
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
unsigned long band = arg - 1;
if (band >= q->bands)
return -EINVAL;
if (new == NULL)
new = &noop_qdisc;
sch_tree_lock(sch);
*old = q->queues[band];
q->queues[band] = new;
qdisc_reset(*old);
sch_tree_unlock(sch);
return 0;
}
static struct Qdisc *
prio_leaf(struct Qdisc *sch, unsigned long arg)
{
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
unsigned long band = arg - 1;
if (band >= q->bands)
return NULL;
return q->queues[band];
}
static unsigned long prio_get(struct Qdisc *sch, u32 classid)
{
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
unsigned long band = TC_H_MIN(classid);
if (band - 1 >= q->bands)
return 0;
return band;
}
static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
{
return prio_get(sch, classid);
}
static void prio_put(struct Qdisc *q, unsigned long cl)
{
return;
}
static int prio_change(struct Qdisc *sch, u32 handle, u32 parent, struct rtattr **tca, unsigned long *arg)
{
unsigned long cl = *arg;
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
if (cl - 1 > q->bands)
return -ENOENT;
return 0;
}
static int prio_delete(struct Qdisc *sch, unsigned long cl)
{
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
if (cl - 1 > q->bands)
return -ENOENT;
return 0;
}
static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
struct tcmsg *tcm)
{
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
if (cl - 1 > q->bands)
return -ENOENT;
if (q->queues[cl-1])
tcm->tcm_info = q->queues[cl-1]->handle;
return 0;
}
static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
{
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
int prio;
if (arg->stop)
return;
for (prio = 0; prio < q->bands; prio++) {
if (arg->count < arg->skip) {
arg->count++;
continue;
}
if (arg->fn(sch, prio+1, arg) < 0) {
arg->stop = 1;
break;
}
arg->count++;
}
}
static struct tcf_proto ** prio_find_tcf(struct Qdisc *sch, unsigned long cl)
{
struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
if (cl)
return NULL;
return &q->filter_list;
}
static struct Qdisc_class_ops prio_class_ops =
{
prio_graft,
prio_leaf,
prio_get,
prio_put,
prio_change,
prio_delete,
prio_walk,
prio_find_tcf,
prio_bind,
prio_put,
prio_dump_class,
};
struct Qdisc_ops prio_qdisc_ops =
{
NULL,
&prio_class_ops,
"prio",
sizeof(struct prio_sched_data),
prio_enqueue,
prio_dequeue,
prio_requeue,
prio_drop,
prio_init,
prio_reset,
prio_destroy,
prio_tune,
prio_dump,
};
#ifdef MODULE
int init_module(void)
{
return register_qdisc(&prio_qdisc_ops);
}
void cleanup_module(void)
{
unregister_qdisc(&prio_qdisc_ops);
}
#endif
MODULE_LICENSE("GPL");
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