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/*
* net/sched/sch_gred.c Generic Random Early Detection 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: J Hadi Salim (hadi@nortelnetworks.com) 1998,1999
*
* 991129: - Bug fix with grio mode
* - a better sing. AvgQ mode with Grio(WRED)
* - A finer grained VQ dequeue based on sugestion
* from Ren Liu
* - More error checks
*
*
*
* For all the glorious comments look at Alexey's sch_red.c
*/
#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>
#if 1 /* control */
#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
#else
#define DPRINTK(format,args...)
#endif
#if 0 /* data */
#define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args)
#else
#define D2PRINTK(format,args...)
#endif
struct gred_sched_data;
struct gred_sched;
struct gred_sched_data
{
/* Parameters */
u32 limit; /* HARD maximal queue length */
u32 qth_min; /* Min average length threshold: A scaled */
u32 qth_max; /* Max average length threshold: A scaled */
u32 DP; /* the drop pramaters */
char Wlog; /* log(W) */
char Plog; /* random number bits */
u32 Scell_max;
u32 Rmask;
u32 bytesin; /* bytes seen on virtualQ so far*/
u32 packetsin; /* packets seen on virtualQ so far*/
u32 backlog; /* bytes on the virtualQ */
u32 forced; /* packets dropped for exceeding limits */
u32 early; /* packets dropped as a warning */
u32 other; /* packets dropped by invoking drop() */
u32 pdrop; /* packets dropped because we exceeded physical queue limits */
char Scell_log;
u8 Stab[256];
u8 prio; /* the prio of this vq */
/* Variables */
unsigned long qave; /* Average queue length: A scaled */
int qcount; /* Packets since last random number generation */
u32 qR; /* Cached random number */
psched_time_t qidlestart; /* Start of idle period */
};
struct gred_sched
{
struct gred_sched_data *tab[MAX_DPs];
u32 DPs;
u32 def;
u8 initd;
u8 grio;
u8 eqp;
};
static int
gred_enqueue(struct sk_buff *skb, struct Qdisc* sch)
{
psched_time_t now;
struct gred_sched_data *q=NULL;
struct gred_sched *t= (struct gred_sched *)sch->data;
unsigned long qave=0;
int i=0;
if (!t->initd && skb_queue_len(&sch->q) <= sch->dev->tx_queue_len) {
D2PRINTK("NO GRED Queues setup yet! Enqueued anyway\n");
goto do_enqueue;
}
if ( ((skb->tc_index&0xf) > t->DPs) || !(q=t->tab[skb->tc_index&0xf])) {
printk("GRED: setting to default (%d)\n ",t->def);
if (!(q=t->tab[t->def])) {
DPRINTK("GRED: setting to default FAILED! dropping!! "
"(%d)\n ", t->def);
goto drop;
}
/* fix tc_index? --could be controvesial but needed for
requeueing */
skb->tc_index=(skb->tc_index&0xfffffff0) | t->def;
}
D2PRINTK("gred_enqueue virtualQ 0x%x classid %x backlog %d "
"general backlog %d\n",skb->tc_index&0xf,sch->handle,q->backlog,
sch->stats.backlog);
/* sum up all the qaves of prios <= to ours to get the new qave*/
if (!t->eqp && t->grio) {
for (i=0;i<t->DPs;i++) {
if ((!t->tab[i]) || (i==q->DP))
continue;
if ((t->tab[i]->prio < q->prio) && (PSCHED_IS_PASTPERFECT(t->tab[i]->qidlestart)))
qave +=t->tab[i]->qave;
}
}
q->packetsin++;
q->bytesin+=skb->len;
if (t->eqp && t->grio) {
qave=0;
q->qave=t->tab[t->def]->qave;
q->qidlestart=t->tab[t->def]->qidlestart;
}
if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) {
long us_idle;
PSCHED_GET_TIME(now);
us_idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max, 0);
PSCHED_SET_PASTPERFECT(q->qidlestart);
q->qave >>= q->Stab[(us_idle>>q->Scell_log)&0xFF];
} else {
if (t->eqp) {
q->qave += sch->stats.backlog - (q->qave >> q->Wlog);
} else {
q->qave += q->backlog - (q->qave >> q->Wlog);
}
}
if (t->eqp && t->grio)
t->tab[t->def]->qave=q->qave;
if ((q->qave+qave) < q->qth_min) {
q->qcount = -1;
enqueue:
if (q->backlog <= q->limit) {
q->backlog += skb->len;
do_enqueue:
__skb_queue_tail(&sch->q, skb);
sch->stats.backlog += skb->len;
sch->stats.bytes += skb->len;
sch->stats.packets++;
return 0;
} else {
q->pdrop++;
}
drop:
kfree_skb(skb);
sch->stats.drops++;
return NET_XMIT_DROP;
}
if ((q->qave+qave) >= q->qth_max) {
q->qcount = -1;
sch->stats.overlimits++;
q->forced++;
goto drop;
}
if (++q->qcount) {
if ((((qave+q->qave) - q->qth_min)>>q->Wlog)*q->qcount < q->qR)
goto enqueue;
q->qcount = 0;
q->qR = net_random()&q->Rmask;
sch->stats.overlimits++;
q->early++;
goto drop;
}
q->qR = net_random()&q->Rmask;
goto enqueue;
}
static int
gred_requeue(struct sk_buff *skb, struct Qdisc* sch)
{
struct gred_sched_data *q;
struct gred_sched *t= (struct gred_sched *)sch->data;
q= t->tab[(skb->tc_index&0xf)];
/* error checking here -- probably unnecessary */
PSCHED_SET_PASTPERFECT(q->qidlestart);
__skb_queue_head(&sch->q, skb);
sch->stats.backlog += skb->len;
q->backlog += skb->len;
return 0;
}
static struct sk_buff *
gred_dequeue(struct Qdisc* sch)
{
struct sk_buff *skb;
struct gred_sched_data *q;
struct gred_sched *t= (struct gred_sched *)sch->data;
skb = __skb_dequeue(&sch->q);
if (skb) {
sch->stats.backlog -= skb->len;
q= t->tab[(skb->tc_index&0xf)];
if (q) {
q->backlog -= skb->len;
if (!q->backlog && !t->eqp)
PSCHED_GET_TIME(q->qidlestart);
} else {
D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf);
}
return skb;
}
if (t->eqp) {
q= t->tab[t->def];
if (!q)
D2PRINTK("no default VQ set: Results will be "
"screwed up\n");
else
PSCHED_GET_TIME(q->qidlestart);
}
return NULL;
}
static int
gred_drop(struct Qdisc* sch)
{
struct sk_buff *skb;
struct gred_sched_data *q;
struct gred_sched *t= (struct gred_sched *)sch->data;
skb = __skb_dequeue_tail(&sch->q);
if (skb) {
sch->stats.backlog -= skb->len;
sch->stats.drops++;
q= t->tab[(skb->tc_index&0xf)];
if (q) {
q->backlog -= skb->len;
q->other++;
if (!q->backlog && !t->eqp)
PSCHED_GET_TIME(q->qidlestart);
} else {
D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf);
}
kfree_skb(skb);
return 1;
}
q=t->tab[t->def];
if (!q) {
D2PRINTK("no default VQ set: Results might be screwed up\n");
return 0;
}
PSCHED_GET_TIME(q->qidlestart);
return 0;
}
static void gred_reset(struct Qdisc* sch)
{
int i;
struct gred_sched_data *q;
struct gred_sched *t= (struct gred_sched *)sch->data;
__skb_queue_purge(&sch->q);
sch->stats.backlog = 0;
for (i=0;i<t->DPs;i++) {
q= t->tab[i];
if (!q)
continue;
PSCHED_SET_PASTPERFECT(q->qidlestart);
q->qave = 0;
q->qcount = -1;
q->backlog = 0;
q->other=0;
q->forced=0;
q->pdrop=0;
q->early=0;
}
}
static int gred_change(struct Qdisc *sch, struct rtattr *opt)
{
struct gred_sched *table = (struct gred_sched *)sch->data;
struct gred_sched_data *q;
struct tc_gred_qopt *ctl;
struct tc_gred_sopt *sopt;
struct rtattr *tb[TCA_GRED_STAB];
struct rtattr *tb2[TCA_GRED_STAB];
int i;
if (opt == NULL ||
rtattr_parse(tb, TCA_GRED_STAB, RTA_DATA(opt), RTA_PAYLOAD(opt)) )
return -EINVAL;
if (tb[TCA_GRED_PARMS-1] == 0 && tb[TCA_GRED_STAB-1] == 0 &&
tb[TCA_GRED_DPS-1] != 0) {
rtattr_parse(tb2, TCA_GRED_DPS, RTA_DATA(opt),
RTA_PAYLOAD(opt));
sopt = RTA_DATA(tb2[TCA_GRED_DPS-1]);
table->DPs=sopt->DPs;
table->def=sopt->def_DP;
table->grio=sopt->grio;
table->initd=0;
/* probably need to clear all the table DP entries as well */
MOD_INC_USE_COUNT;
return 0;
}
if (!table->DPs || tb[TCA_GRED_PARMS-1] == 0 || tb[TCA_GRED_STAB-1] == 0 ||
RTA_PAYLOAD(tb[TCA_GRED_PARMS-1]) < sizeof(*ctl) ||
RTA_PAYLOAD(tb[TCA_GRED_STAB-1]) < 256)
return -EINVAL;
ctl = RTA_DATA(tb[TCA_GRED_PARMS-1]);
if (ctl->DP > MAX_DPs-1 ) {
/* misbehaving is punished! Put in the default drop probability */
DPRINTK("\nGRED: DP %u not in the proper range fixed. New DP "
"set to default at %d\n",ctl->DP,table->def);
ctl->DP=table->def;
}
if (table->tab[ctl->DP] == NULL) {
table->tab[ctl->DP]=kmalloc(sizeof(struct gred_sched_data),
GFP_KERNEL);
if (NULL == table->tab[ctl->DP])
return -ENOMEM;
memset(table->tab[ctl->DP], 0, (sizeof(struct gred_sched_data)));
}
q= table->tab[ctl->DP];
if (table->grio) {
if (ctl->prio <=0) {
if (table->def && table->tab[table->def]) {
DPRINTK("\nGRED: DP %u does not have a prio"
"setting default to %d\n",ctl->DP,
table->tab[table->def]->prio);
q->prio=table->tab[table->def]->prio;
} else {
DPRINTK("\nGRED: DP %u does not have a prio"
" setting default to 8\n",ctl->DP);
q->prio=8;
}
} else {
q->prio=ctl->prio;
}
} else {
q->prio=8;
}
q->DP=ctl->DP;
q->Wlog = ctl->Wlog;
q->Plog = ctl->Plog;
q->limit = ctl->limit;
q->Scell_log = ctl->Scell_log;
q->Rmask = ctl->Plog < 32 ? ((1<<ctl->Plog) - 1) : ~0UL;
q->Scell_max = (255<<q->Scell_log);
q->qth_min = ctl->qth_min<<ctl->Wlog;
q->qth_max = ctl->qth_max<<ctl->Wlog;
q->qave=0;
q->backlog=0;
q->qcount = -1;
q->other=0;
q->forced=0;
q->pdrop=0;
q->early=0;
PSCHED_SET_PASTPERFECT(q->qidlestart);
memcpy(q->Stab, RTA_DATA(tb[TCA_GRED_STAB-1]), 256);
if ( table->initd && table->grio) {
/* this looks ugly but its not in the fast path */
for (i=0;i<table->DPs;i++) {
if ((!table->tab[i]) || (i==q->DP) )
continue;
if (table->tab[i]->prio == q->prio ){
/* WRED mode detected */
table->eqp=1;
break;
}
}
}
if (!table->initd) {
table->initd=1;
/*
the first entry also goes into the default until
over-written
*/
if (table->tab[table->def] == NULL) {
table->tab[table->def]=
kmalloc(sizeof(struct gred_sched_data), GFP_KERNEL);
if (NULL == table->tab[ctl->DP])
return -ENOMEM;
memset(table->tab[table->def], 0,
(sizeof(struct gred_sched_data)));
}
q= table->tab[table->def];
q->DP=table->def;
q->Wlog = ctl->Wlog;
q->Plog = ctl->Plog;
q->limit = ctl->limit;
q->Scell_log = ctl->Scell_log;
q->Rmask = ctl->Plog < 32 ? ((1<<ctl->Plog) - 1) : ~0UL;
q->Scell_max = (255<<q->Scell_log);
q->qth_min = ctl->qth_min<<ctl->Wlog;
q->qth_max = ctl->qth_max<<ctl->Wlog;
if (table->grio)
q->prio=table->tab[ctl->DP]->prio;
else
q->prio=8;
q->qcount = -1;
PSCHED_SET_PASTPERFECT(q->qidlestart);
memcpy(q->Stab, RTA_DATA(tb[TCA_GRED_STAB-1]), 256);
}
return 0;
}
static int gred_init(struct Qdisc *sch, struct rtattr *opt)
{
struct gred_sched *table = (struct gred_sched *)sch->data;
struct tc_gred_sopt *sopt;
struct rtattr *tb[TCA_GRED_STAB];
struct rtattr *tb2[TCA_GRED_STAB];
if (opt == NULL ||
rtattr_parse(tb, TCA_GRED_STAB, RTA_DATA(opt), RTA_PAYLOAD(opt)) )
return -EINVAL;
if (tb[TCA_GRED_PARMS-1] == 0 && tb[TCA_GRED_STAB-1] == 0 &&
tb[TCA_GRED_DPS-1] != 0) {
rtattr_parse(tb2, TCA_GRED_DPS, RTA_DATA(opt),RTA_PAYLOAD(opt));
sopt = RTA_DATA(tb2[TCA_GRED_DPS-1]);
table->DPs=sopt->DPs;
table->def=sopt->def_DP;
table->grio=sopt->grio;
table->initd=0;
MOD_INC_USE_COUNT;
return 0;
}
DPRINTK("\n GRED_INIT error!\n");
return -EINVAL;
}
static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
{
unsigned long qave;
struct rtattr *rta;
struct tc_gred_qopt *opt;
struct tc_gred_qopt *dst;
struct gred_sched *table = (struct gred_sched *)sch->data;
struct gred_sched_data *q;
int i;
unsigned char *b = skb->tail;
rta = (struct rtattr*)b;
RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
opt=kmalloc(sizeof(struct tc_gred_qopt)*MAX_DPs, GFP_KERNEL);
if (opt == NULL) {
DPRINTK("gred_dump:failed to malloc for %Zd\n",
sizeof(struct tc_gred_qopt)*MAX_DPs);
goto rtattr_failure;
}
memset(opt, 0, (sizeof(struct tc_gred_qopt))*table->DPs);
if (!table->initd) {
DPRINTK("NO GRED Queues setup!\n");
return -1;
}
for (i=0;i<MAX_DPs;i++) {
dst= &opt[i];
q= table->tab[i];
if (!q) {
/* hack -- fix at some point with proper message
This is how we indicate to tc that there is no VQ
at this DP */
dst->DP=MAX_DPs+i;
continue;
}
dst->limit=q->limit;
dst->qth_min=q->qth_min>>q->Wlog;
dst->qth_max=q->qth_max>>q->Wlog;
dst->DP=q->DP;
dst->backlog=q->backlog;
if (q->qave) {
if (table->eqp && table->grio) {
q->qidlestart=table->tab[table->def]->qidlestart;
q->qave=table->tab[table->def]->qave;
}
if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) {
long idle;
psched_time_t now;
PSCHED_GET_TIME(now);
idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max, 0);
qave = q->qave >> q->Stab[(idle>>q->Scell_log)&0xFF];
dst->qave = qave >> q->Wlog;
} else {
dst->qave = q->qave >> q->Wlog;
}
} else {
dst->qave = 0;
}
dst->Wlog = q->Wlog;
dst->Plog = q->Plog;
dst->Scell_log = q->Scell_log;
dst->other = q->other;
dst->forced = q->forced;
dst->early = q->early;
dst->pdrop = q->pdrop;
dst->prio = q->prio;
dst->packets=q->packetsin;
dst->bytesin=q->bytesin;
}
RTA_PUT(skb, TCA_GRED_PARMS, sizeof(struct tc_gred_qopt)*MAX_DPs, opt);
rta->rta_len = skb->tail - b;
return skb->len;
rtattr_failure:
DPRINTK("gred_dump: FAILURE!!!!\n");
/* also free the opt struct here */
skb_trim(skb, b - skb->data);
return -1;
}
static void gred_destroy(struct Qdisc *sch)
{
struct gred_sched *table = (struct gred_sched *)sch->data;
int i;
for (i = 0;i < table->DPs; i++) {
if (table->tab[i])
kfree(table->tab[i]);
}
MOD_DEC_USE_COUNT;
}
struct Qdisc_ops gred_qdisc_ops =
{
NULL,
NULL,
"gred",
sizeof(struct gred_sched),
gred_enqueue,
gred_dequeue,
gred_requeue,
gred_drop,
gred_init,
gred_reset,
gred_destroy,
gred_change, /* change */
gred_dump,
};
#ifdef MODULE
int init_module(void)
{
return register_qdisc(&gred_qdisc_ops);
}
void cleanup_module(void)
{
unregister_qdisc(&gred_qdisc_ops);
}
#endif
MODULE_LICENSE("GPL");
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