[PATCH] Add selective delay to sch_dealy (aka sch_ooo)

@@ -7,6 +7,7 @@
   * 		2 of the License, or (at your option) any later version.
   *
   * Authors:	Stephen Hemminger <shemminger@osdl.org>
+		Catalin(ux aka Dino) BOIE <catab at umbrella dot ro>
   */

  #include <linux/config.h>

@@ -33,7 +34,7 @@
  #include <net/pkt_sched.h>

  /*	Network delay simulator
-	This scheduler adds a fixed delay to all packets.
+	This scheduler adds a fixed delay to all/some packets.
  	Similar to NISTnet and BSD Dummynet.

  	It uses byte fifo underneath similar to TBF */

@@ -41,8 +42,12 @@ struct dly_sched_data {
  	u32	latency;
  	u32	limit;
  	u32	loss;
+	u32	gap;	/* gap between packets: 0=all pkts are processed */
  	struct timer_list timer;
  	struct Qdisc *qdisc;
+	struct sk_buff_head qooo;
+	u32	send_from_qooo;
+	u32	counter;
  };

  /* Time stamp put into socket buffer control block */

@@ -59,6 +64,8 @@ static int dly_enqueue(struct sk_buff *s
  	struct dly_skb_cb *cb = (struct dly_skb_cb *)skb->cb;
  	int ret;

+	pr_debug("enqueue:\n");
+
  	/* Random packet drop 0 => none, ~0 => all */
  	if (q->loss >= net_random()) {
  		sch->stats.drops++;

@@ -104,6 +111,26 @@ static unsigned int dly_drop(struct Qdis
  	return len;
  }

+static void dly_mod_timer(struct dly_sched_data *q, struct sk_buff *skb)
+{
+	struct dly_skb_cb	*cb;
+	psched_time_t		now;
+	long			diff, delay;
+
+	if (timer_pending(&q->timer))
+		return;
+
+	cb = (struct dly_skb_cb *)skb->cb;
+	PSCHED_GET_TIME(now);
+	diff = q->latency - PSCHED_TDIFF(now, cb->queuetime);
+	delay = PSCHED_US2JIFFIE(diff);
+	if (delay <= 0)
+		delay = 1;
+	mod_timer(&q->timer, jiffies + delay);
+
+	pr_debug("mod_timer: Set new timer to %ld\n", jiffies + delay);
+}
+
  /* Dequeue packet.
   * If packet needs to be held up, then stop the
   * queue and set timer to wakeup later.

@@ -111,37 +138,54 @@ static unsigned int dly_drop(struct Qdis
  static struct sk_buff *dly_dequeue(struct Qdisc *sch)
  {
  	struct dly_sched_data *q = (struct dly_sched_data *)sch->data;
-	struct sk_buff *skb;
+	struct sk_buff *skb, *skb2;

- retry:
-	skb = q->qdisc->dequeue(q->qdisc);
-	if (skb) {
-		struct dly_skb_cb *cb = (struct dly_skb_cb *)skb->cb;
-		psched_time_t now;
-		long diff, delay;
-
-		PSCHED_GET_TIME(now);
-		diff = q->latency - PSCHED_TDIFF(now, cb->queuetime);
-
-		if (diff <= 0) {
-			sch->q.qlen--;
-			sch->flags &= ~TCQ_F_THROTTLED;
-			return skb;
+	/* test if we must dequeue from qooo */
+	if (q->send_from_qooo == 1) {
+		q->send_from_qooo = 0;
+
+		skb = __skb_dequeue(&q->qooo);
+		if (skb == NULL) {
+			pr_debug("dequeue: BUG! send_from_qooo == 1 and queue 

@@ -153,11 +197,16 @@ static void dly_reset(struct Qdisc *sch)
  	sch->q.qlen = 0;
  	sch->flags &= ~TCQ_F_THROTTLED;
  	del_timer(&q->timer);
+	skb_queue_purge(&q->qooo);
  }

  static void dly_timer(unsigned long arg)
  {
  	struct Qdisc *sch = (struct Qdisc *)arg;
+	struct dly_sched_data *q = (struct dly_sched_data *)sch->data;
+
+	pr_debug("timer: Permit sending from qooo\n");
+	q->send_from_qooo = 1;

  	sch->flags &= ~TCQ_F_THROTTLED;
  	netif_schedule(sch->dev);

@@ -205,6 +254,10 @@ static int dly_change(struct Qdisc *sch,
  		q->latency = qopt->latency;
  		q->limit = qopt->limit;
  		q->loss = qopt->loss;
+		q->gap = qopt->gap;
+
+		q->counter = 0;
+		q->send_from_qooo = 0;
  	}
  	return err;
  }

@@ -221,6 +274,8 @@ static int dly_init(struct Qdisc *sch, s
  	q->timer.data = (unsigned long) sch;
  	q->qdisc = &noop_qdisc;

+	skb_queue_head_init(&q->qooo);
+
  	return dly_change(sch, opt);
  }

@@ -231,6 +286,7 @@ static void dly_destroy(struct Qdisc *sc
  	del_timer(&q->timer);
  	qdisc_destroy(q->qdisc);
  	q->qdisc = &noop_qdisc;
+	skb_queue_purge(&q->qooo);
  }

  static int dly_dump(struct Qdisc *sch, struct sk_buff *skb)

@@ -242,6 +298,7 @@ static int dly_dump(struct Qdisc *sch, s
  	qopt.latency = q->latency;
  	qopt.limit = q->limit;
  	qopt.loss = q->loss;
+	qopt.gap = q->gap;

  	RTA_PUT(skb, TCA_OPTIONS, sizeof(qopt), &qopt);

--- linux-2.6.7-bk5.orig/include/linux/pkt_sched.h	2004-06-23 

@@ -438,5 +438,6 @@ struct tc_dly_qopt
  	__u32	latency;
  	__u32   limit;
  	__u32	loss;
+	__u32	gap;
  };
  #endif