patch-2.3.38 linux/net/sched/sch_gred.c

• Lines: 607
• Date: Fri Jan 7 16:57:13 2000
• Orig file: v2.3.37/linux/net/sched/sch_gred.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.37/linux/net/sched/sch_gred.c linux/net/sched/sch_gred.c
@@ -0,0 +1,606 @@
+/*
+ * 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
+ *		       - A finer grained VQ dequeue based on sugestion
+ *		         from Ren Liu
+ *
+ *
+ *
+ *  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) {
+		DPRINTK("NO GRED Queues setup yet! Enqueued anyway\n");
+		if (q->backlog <= q->limit) {
+			__skb_queue_tail(&sch->q, skb);
+			return NET_XMIT_DROP; /* @@@@ */
+		}
+	}
+
+
+	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->grio) {
+		for (i=0;i<t->DPs;i++) {
+			if ((!t->tab[i]) || (i==q->DP))	
+				continue; 
+			if (t->tab[i]->prio == q->prio ){
+				qave=0;
+				t->eqp=1;
+				q->qave=t->tab[t->def]->qave;
+				q->qidlestart=t->tab[t->def]->qidlestart;
+				break;
+			}
+				
+			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 (!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 {
+		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) {
+			__skb_queue_tail(&sch->q, skb);
+			sch->stats.backlog += skb->len;
+			sch->stats.bytes += skb->len;
+			sch->stats.packets++;
+			q->backlog += skb->len;
+			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) {
+		q= t->tab[(skb->tc_index&0xf)];
+		sch->stats.backlog -= skb->len;
+		q->backlog -= skb->len;
+		if (!q->backlog && !t->eqp)
+			PSCHED_GET_TIME(q->qidlestart);
+		return skb;
+	}
+
+	if (t->eqp) {
+			q= t->tab[t->def];
+			if (!q)	
+				printk("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;
+	int i;
+
+	struct gred_sched_data *q;
+	struct gred_sched *t= (struct gred_sched *)sch->data;
+
+	skb = __skb_dequeue_tail(&sch->q);
+	if (skb) {
+		q= t->tab[(skb->tc_index&0xf)];
+		sch->stats.backlog -= skb->len;
+		sch->stats.drops++;
+		q->backlog -= skb->len;
+		q->other++;
+		kfree_skb(skb);
+		return 1;
+	}
+
+/* could probably do it for a single VQ before freeing the skb */
+        for (i=0;i<t->DPs;i++) {
+	        q= t->tab[i];
+		if (!q)	
+			continue; 
+        	PSCHED_GET_TIME(q->qidlestart);
+        }
+
+	return 0;
+}
+
+static void gred_reset(struct Qdisc* sch)
+{
+	struct sk_buff *skb;
+	int i;
+
+	struct gred_sched_data *q;
+	struct gred_sched *t= (struct gred_sched *)sch->data;
+
+	while((skb=__skb_dequeue(&sch->q))!=NULL)
+		kfree_skb(skb);
+	sch->stats.backlog = 0;
+
+/* could probably do it for a single VQ before freeing the skb */
+        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];
+
+        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 || ctl->DP <0) {
+		/* 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);
+	        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->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);
+			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;
+}
+
+#ifdef CONFIG_RTNETLINK
+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 %d\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;
+}
+#endif
+
+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 */
+#ifdef CONFIG_RTNETLINK
+	gred_dump,
+#endif
+};
+
+
+#ifdef MODULE
+int init_module(void)
+{
+	return register_qdisc(&gred_qdisc_ops);
+}
+
+void cleanup_module(void) 
+{
+	unregister_qdisc(&gred_qdisc_ops);
+}
+#endif