614 lines
14 KiB
C
614 lines
14 KiB
C
/*
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* net/sched/sch_gred.c Generic Random Early Detection queue.
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*
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Authors: J Hadi Salim (hadi@cyberus.ca) 1998-2002
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*
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* 991129: - Bug fix with grio mode
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* - a better sing. AvgQ mode with Grio(WRED)
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* - A finer grained VQ dequeue based on sugestion
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* from Ren Liu
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* - More error checks
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*
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* For all the glorious comments look at include/net/red.h
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*/
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/skbuff.h>
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#include <net/pkt_sched.h>
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#include <net/red.h>
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#define GRED_DEF_PRIO (MAX_DPs / 2)
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#define GRED_VQ_MASK (MAX_DPs - 1)
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struct gred_sched_data;
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struct gred_sched;
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struct gred_sched_data
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{
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u32 limit; /* HARD maximal queue length */
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u32 DP; /* the drop pramaters */
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u32 bytesin; /* bytes seen on virtualQ so far*/
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u32 packetsin; /* packets seen on virtualQ so far*/
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u32 backlog; /* bytes on the virtualQ */
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u8 prio; /* the prio of this vq */
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struct red_parms parms;
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struct red_stats stats;
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};
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enum {
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GRED_WRED_MODE = 1,
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GRED_RIO_MODE,
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};
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struct gred_sched
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{
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struct gred_sched_data *tab[MAX_DPs];
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unsigned long flags;
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u32 red_flags;
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u32 DPs;
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u32 def;
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struct red_parms wred_set;
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};
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static inline int gred_wred_mode(struct gred_sched *table)
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{
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return test_bit(GRED_WRED_MODE, &table->flags);
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}
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static inline void gred_enable_wred_mode(struct gred_sched *table)
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{
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__set_bit(GRED_WRED_MODE, &table->flags);
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}
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static inline void gred_disable_wred_mode(struct gred_sched *table)
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{
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__clear_bit(GRED_WRED_MODE, &table->flags);
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}
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static inline int gred_rio_mode(struct gred_sched *table)
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{
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return test_bit(GRED_RIO_MODE, &table->flags);
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}
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static inline void gred_enable_rio_mode(struct gred_sched *table)
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{
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__set_bit(GRED_RIO_MODE, &table->flags);
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}
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static inline void gred_disable_rio_mode(struct gred_sched *table)
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{
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__clear_bit(GRED_RIO_MODE, &table->flags);
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}
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static inline int gred_wred_mode_check(struct Qdisc *sch)
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{
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struct gred_sched *table = qdisc_priv(sch);
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int i;
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/* Really ugly O(n^2) but shouldn't be necessary too frequent. */
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for (i = 0; i < table->DPs; i++) {
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struct gred_sched_data *q = table->tab[i];
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int n;
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if (q == NULL)
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continue;
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for (n = 0; n < table->DPs; n++)
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if (table->tab[n] && table->tab[n] != q &&
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table->tab[n]->prio == q->prio)
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return 1;
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}
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return 0;
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}
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static inline unsigned int gred_backlog(struct gred_sched *table,
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struct gred_sched_data *q,
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struct Qdisc *sch)
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{
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if (gred_wred_mode(table))
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return sch->qstats.backlog;
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else
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return q->backlog;
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}
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static inline u16 tc_index_to_dp(struct sk_buff *skb)
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{
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return skb->tc_index & GRED_VQ_MASK;
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}
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static inline void gred_load_wred_set(struct gred_sched *table,
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struct gred_sched_data *q)
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{
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q->parms.qavg = table->wred_set.qavg;
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q->parms.qidlestart = table->wred_set.qidlestart;
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}
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static inline void gred_store_wred_set(struct gred_sched *table,
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struct gred_sched_data *q)
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{
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table->wred_set.qavg = q->parms.qavg;
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}
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static inline int gred_use_ecn(struct gred_sched *t)
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{
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return t->red_flags & TC_RED_ECN;
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}
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static inline int gred_use_harddrop(struct gred_sched *t)
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{
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return t->red_flags & TC_RED_HARDDROP;
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}
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static int gred_enqueue(struct sk_buff *skb, struct Qdisc* sch)
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{
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struct gred_sched_data *q=NULL;
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struct gred_sched *t= qdisc_priv(sch);
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unsigned long qavg = 0;
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u16 dp = tc_index_to_dp(skb);
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if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
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dp = t->def;
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if ((q = t->tab[dp]) == NULL) {
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/* Pass through packets not assigned to a DP
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* if no default DP has been configured. This
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* allows for DP flows to be left untouched.
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*/
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if (skb_queue_len(&sch->q) < sch->dev->tx_queue_len)
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return qdisc_enqueue_tail(skb, sch);
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else
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goto drop;
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}
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/* fix tc_index? --could be controvesial but needed for
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requeueing */
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skb->tc_index = (skb->tc_index & ~GRED_VQ_MASK) | dp;
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}
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/* sum up all the qaves of prios <= to ours to get the new qave */
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if (!gred_wred_mode(t) && gred_rio_mode(t)) {
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int i;
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for (i = 0; i < t->DPs; i++) {
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if (t->tab[i] && t->tab[i]->prio < q->prio &&
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!red_is_idling(&t->tab[i]->parms))
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qavg +=t->tab[i]->parms.qavg;
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}
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}
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q->packetsin++;
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q->bytesin += skb->len;
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if (gred_wred_mode(t))
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gred_load_wred_set(t, q);
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q->parms.qavg = red_calc_qavg(&q->parms, gred_backlog(t, q, sch));
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if (red_is_idling(&q->parms))
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red_end_of_idle_period(&q->parms);
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if (gred_wred_mode(t))
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gred_store_wred_set(t, q);
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switch (red_action(&q->parms, q->parms.qavg + qavg)) {
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case RED_DONT_MARK:
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break;
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case RED_PROB_MARK:
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sch->qstats.overlimits++;
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if (!gred_use_ecn(t) || !INET_ECN_set_ce(skb)) {
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q->stats.prob_drop++;
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goto congestion_drop;
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}
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q->stats.prob_mark++;
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break;
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case RED_HARD_MARK:
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sch->qstats.overlimits++;
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if (gred_use_harddrop(t) || !gred_use_ecn(t) ||
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!INET_ECN_set_ce(skb)) {
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q->stats.forced_drop++;
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goto congestion_drop;
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}
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q->stats.forced_mark++;
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break;
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}
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if (q->backlog + skb->len <= q->limit) {
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q->backlog += skb->len;
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return qdisc_enqueue_tail(skb, sch);
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}
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q->stats.pdrop++;
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drop:
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return qdisc_drop(skb, sch);
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congestion_drop:
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qdisc_drop(skb, sch);
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return NET_XMIT_CN;
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}
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static int gred_requeue(struct sk_buff *skb, struct Qdisc* sch)
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{
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struct gred_sched *t = qdisc_priv(sch);
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struct gred_sched_data *q;
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u16 dp = tc_index_to_dp(skb);
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if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
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if (net_ratelimit())
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printk(KERN_WARNING "GRED: Unable to relocate VQ 0x%x "
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"for requeue, screwing up backlog.\n",
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tc_index_to_dp(skb));
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} else {
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if (red_is_idling(&q->parms))
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red_end_of_idle_period(&q->parms);
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q->backlog += skb->len;
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}
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return qdisc_requeue(skb, sch);
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}
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static struct sk_buff *gred_dequeue(struct Qdisc* sch)
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{
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struct sk_buff *skb;
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struct gred_sched *t = qdisc_priv(sch);
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skb = qdisc_dequeue_head(sch);
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if (skb) {
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struct gred_sched_data *q;
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u16 dp = tc_index_to_dp(skb);
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if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
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if (net_ratelimit())
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printk(KERN_WARNING "GRED: Unable to relocate "
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"VQ 0x%x after dequeue, screwing up "
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"backlog.\n", tc_index_to_dp(skb));
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} else {
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q->backlog -= skb->len;
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if (!q->backlog && !gred_wred_mode(t))
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red_start_of_idle_period(&q->parms);
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}
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return skb;
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}
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if (gred_wred_mode(t) && !red_is_idling(&t->wred_set))
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red_start_of_idle_period(&t->wred_set);
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return NULL;
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}
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static unsigned int gred_drop(struct Qdisc* sch)
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{
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struct sk_buff *skb;
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struct gred_sched *t = qdisc_priv(sch);
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skb = qdisc_dequeue_tail(sch);
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if (skb) {
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unsigned int len = skb->len;
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struct gred_sched_data *q;
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u16 dp = tc_index_to_dp(skb);
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if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
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if (net_ratelimit())
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printk(KERN_WARNING "GRED: Unable to relocate "
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"VQ 0x%x while dropping, screwing up "
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"backlog.\n", tc_index_to_dp(skb));
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} else {
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q->backlog -= len;
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q->stats.other++;
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if (!q->backlog && !gred_wred_mode(t))
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red_start_of_idle_period(&q->parms);
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}
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qdisc_drop(skb, sch);
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return len;
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}
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if (gred_wred_mode(t) && !red_is_idling(&t->wred_set))
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red_start_of_idle_period(&t->wred_set);
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return 0;
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}
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static void gred_reset(struct Qdisc* sch)
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{
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int i;
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struct gred_sched *t = qdisc_priv(sch);
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qdisc_reset_queue(sch);
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for (i = 0; i < t->DPs; i++) {
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struct gred_sched_data *q = t->tab[i];
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if (!q)
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continue;
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red_restart(&q->parms);
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q->backlog = 0;
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}
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}
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static inline void gred_destroy_vq(struct gred_sched_data *q)
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{
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kfree(q);
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}
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static inline int gred_change_table_def(struct Qdisc *sch, struct nlattr *dps)
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{
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struct gred_sched *table = qdisc_priv(sch);
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struct tc_gred_sopt *sopt;
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int i;
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if (dps == NULL || nla_len(dps) < sizeof(*sopt))
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return -EINVAL;
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sopt = nla_data(dps);
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if (sopt->DPs > MAX_DPs || sopt->DPs == 0 || sopt->def_DP >= sopt->DPs)
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return -EINVAL;
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sch_tree_lock(sch);
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table->DPs = sopt->DPs;
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table->def = sopt->def_DP;
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table->red_flags = sopt->flags;
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/*
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* Every entry point to GRED is synchronized with the above code
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* and the DP is checked against DPs, i.e. shadowed VQs can no
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* longer be found so we can unlock right here.
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*/
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sch_tree_unlock(sch);
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if (sopt->grio) {
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gred_enable_rio_mode(table);
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gred_disable_wred_mode(table);
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if (gred_wred_mode_check(sch))
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gred_enable_wred_mode(table);
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} else {
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gred_disable_rio_mode(table);
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gred_disable_wred_mode(table);
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}
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for (i = table->DPs; i < MAX_DPs; i++) {
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if (table->tab[i]) {
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printk(KERN_WARNING "GRED: Warning: Destroying "
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"shadowed VQ 0x%x\n", i);
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gred_destroy_vq(table->tab[i]);
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table->tab[i] = NULL;
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}
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}
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return 0;
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}
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static inline int gred_change_vq(struct Qdisc *sch, int dp,
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struct tc_gred_qopt *ctl, int prio, u8 *stab)
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{
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struct gred_sched *table = qdisc_priv(sch);
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struct gred_sched_data *q;
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if (table->tab[dp] == NULL) {
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table->tab[dp] = kzalloc(sizeof(*q), GFP_KERNEL);
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if (table->tab[dp] == NULL)
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return -ENOMEM;
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}
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q = table->tab[dp];
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q->DP = dp;
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q->prio = prio;
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q->limit = ctl->limit;
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if (q->backlog == 0)
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red_end_of_idle_period(&q->parms);
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red_set_parms(&q->parms,
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ctl->qth_min, ctl->qth_max, ctl->Wlog, ctl->Plog,
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ctl->Scell_log, stab);
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return 0;
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}
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static int gred_change(struct Qdisc *sch, struct nlattr *opt)
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{
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struct gred_sched *table = qdisc_priv(sch);
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struct tc_gred_qopt *ctl;
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struct nlattr *tb[TCA_GRED_MAX + 1];
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int err = -EINVAL, prio = GRED_DEF_PRIO;
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u8 *stab;
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if (opt == NULL || nla_parse_nested(tb, TCA_GRED_MAX, opt, NULL))
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return -EINVAL;
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if (tb[TCA_GRED_PARMS] == NULL && tb[TCA_GRED_STAB] == NULL)
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return gred_change_table_def(sch, opt);
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if (tb[TCA_GRED_PARMS] == NULL ||
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nla_len(tb[TCA_GRED_PARMS]) < sizeof(*ctl) ||
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tb[TCA_GRED_STAB] == NULL ||
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nla_len(tb[TCA_GRED_STAB]) < 256)
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return -EINVAL;
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ctl = nla_data(tb[TCA_GRED_PARMS]);
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stab = nla_data(tb[TCA_GRED_STAB]);
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if (ctl->DP >= table->DPs)
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goto errout;
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if (gred_rio_mode(table)) {
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if (ctl->prio == 0) {
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int def_prio = GRED_DEF_PRIO;
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if (table->tab[table->def])
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def_prio = table->tab[table->def]->prio;
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printk(KERN_DEBUG "GRED: DP %u does not have a prio "
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"setting default to %d\n", ctl->DP, def_prio);
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prio = def_prio;
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} else
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prio = ctl->prio;
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}
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sch_tree_lock(sch);
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err = gred_change_vq(sch, ctl->DP, ctl, prio, stab);
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if (err < 0)
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goto errout_locked;
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if (gred_rio_mode(table)) {
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gred_disable_wred_mode(table);
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if (gred_wred_mode_check(sch))
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gred_enable_wred_mode(table);
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}
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err = 0;
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errout_locked:
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sch_tree_unlock(sch);
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errout:
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return err;
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}
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static int gred_init(struct Qdisc *sch, struct nlattr *opt)
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{
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struct nlattr *tb[TCA_GRED_MAX + 1];
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if (opt == NULL || nla_parse_nested(tb, TCA_GRED_MAX, opt, NULL))
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return -EINVAL;
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if (tb[TCA_GRED_PARMS] || tb[TCA_GRED_STAB])
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return -EINVAL;
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return gred_change_table_def(sch, tb[TCA_GRED_DPS]);
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}
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static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
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{
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struct gred_sched *table = qdisc_priv(sch);
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struct nlattr *parms, *opts = NULL;
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int i;
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struct tc_gred_sopt sopt = {
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.DPs = table->DPs,
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.def_DP = table->def,
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.grio = gred_rio_mode(table),
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.flags = table->red_flags,
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};
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opts = nla_nest_start(skb, TCA_OPTIONS);
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if (opts == NULL)
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goto nla_put_failure;
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NLA_PUT(skb, TCA_GRED_DPS, sizeof(sopt), &sopt);
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parms = nla_nest_start(skb, TCA_GRED_PARMS);
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if (parms == NULL)
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goto nla_put_failure;
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|
for (i = 0; i < MAX_DPs; i++) {
|
|
struct gred_sched_data *q = table->tab[i];
|
|
struct tc_gred_qopt opt;
|
|
|
|
memset(&opt, 0, sizeof(opt));
|
|
|
|
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 */
|
|
|
|
opt.DP = MAX_DPs + i;
|
|
goto append_opt;
|
|
}
|
|
|
|
opt.limit = q->limit;
|
|
opt.DP = q->DP;
|
|
opt.backlog = q->backlog;
|
|
opt.prio = q->prio;
|
|
opt.qth_min = q->parms.qth_min >> q->parms.Wlog;
|
|
opt.qth_max = q->parms.qth_max >> q->parms.Wlog;
|
|
opt.Wlog = q->parms.Wlog;
|
|
opt.Plog = q->parms.Plog;
|
|
opt.Scell_log = q->parms.Scell_log;
|
|
opt.other = q->stats.other;
|
|
opt.early = q->stats.prob_drop;
|
|
opt.forced = q->stats.forced_drop;
|
|
opt.pdrop = q->stats.pdrop;
|
|
opt.packets = q->packetsin;
|
|
opt.bytesin = q->bytesin;
|
|
|
|
if (gred_wred_mode(table)) {
|
|
q->parms.qidlestart =
|
|
table->tab[table->def]->parms.qidlestart;
|
|
q->parms.qavg = table->tab[table->def]->parms.qavg;
|
|
}
|
|
|
|
opt.qave = red_calc_qavg(&q->parms, q->parms.qavg);
|
|
|
|
append_opt:
|
|
if (nla_append(skb, sizeof(opt), &opt) < 0)
|
|
goto nla_put_failure;
|
|
}
|
|
|
|
nla_nest_end(skb, parms);
|
|
|
|
return nla_nest_end(skb, opts);
|
|
|
|
nla_put_failure:
|
|
return nla_nest_cancel(skb, opts);
|
|
}
|
|
|
|
static void gred_destroy(struct Qdisc *sch)
|
|
{
|
|
struct gred_sched *table = qdisc_priv(sch);
|
|
int i;
|
|
|
|
for (i = 0; i < table->DPs; i++) {
|
|
if (table->tab[i])
|
|
gred_destroy_vq(table->tab[i]);
|
|
}
|
|
}
|
|
|
|
static struct Qdisc_ops gred_qdisc_ops __read_mostly = {
|
|
.id = "gred",
|
|
.priv_size = sizeof(struct gred_sched),
|
|
.enqueue = gred_enqueue,
|
|
.dequeue = gred_dequeue,
|
|
.requeue = gred_requeue,
|
|
.drop = gred_drop,
|
|
.init = gred_init,
|
|
.reset = gred_reset,
|
|
.destroy = gred_destroy,
|
|
.change = gred_change,
|
|
.dump = gred_dump,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int __init gred_module_init(void)
|
|
{
|
|
return register_qdisc(&gred_qdisc_ops);
|
|
}
|
|
|
|
static void __exit gred_module_exit(void)
|
|
{
|
|
unregister_qdisc(&gred_qdisc_ops);
|
|
}
|
|
|
|
module_init(gred_module_init)
|
|
module_exit(gred_module_exit)
|
|
|
|
MODULE_LICENSE("GPL");
|