[deliverable/linux.git] / net / sched / sch_red.c

/*
 * net/sched/sch_red.c	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:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 * Changes:
 * J Hadi Salim 980914:	computation fixes
 * Alexey Makarenko <makar@phoenix.kharkov.ua> 990814: qave on idle link was calculated incorrectly.
 * J Hadi Salim 980816:  ECN support
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <net/pkt_sched.h>
#include <net/inet_ecn.h>
#include <net/red.h>


/*	Parameters, settable by user:
	-----------------------------

	limit		- bytes (must be > qth_max + burst)

	Hard limit on queue length, should be chosen >qth_max
	to allow packet bursts. This parameter does not
	affect the algorithms behaviour and can be chosen
	arbitrarily high (well, less than ram size)
	Really, this limit will never be reached
	if RED works correctly.
 */

struct red_sched_data
{
	u32			limit;		/* HARD maximal queue length */
	unsigned char		flags;
	struct red_parms	parms;
	struct red_stats	stats;
	struct Qdisc		*qdisc;
};

static inline int red_use_ecn(struct red_sched_data *q)
{
	return q->flags & TC_RED_ECN;
}

static inline int red_use_harddrop(struct red_sched_data *q)
{
	return q->flags & TC_RED_HARDDROP;
}

static int red_enqueue(struct sk_buff *skb, struct Qdisc* sch)
{
	struct red_sched_data *q = qdisc_priv(sch);
	struct Qdisc *child = q->qdisc;
	int ret;

	q->parms.qavg = red_calc_qavg(&q->parms, child->qstats.backlog);

	if (red_is_idling(&q->parms))
		red_end_of_idle_period(&q->parms);

	switch (red_action(&q->parms, q->parms.qavg)) {
		case RED_DONT_MARK:
			break;

		case RED_PROB_MARK:
			sch->qstats.overlimits++;
			if (!red_use_ecn(q) || !INET_ECN_set_ce(skb)) {
				q->stats.prob_drop++;
				goto congestion_drop;
			}

			q->stats.prob_mark++;
			break;

		case RED_HARD_MARK:
			sch->qstats.overlimits++;
			if (red_use_harddrop(q) || !red_use_ecn(q) ||
			    !INET_ECN_set_ce(skb)) {
				q->stats.forced_drop++;
				goto congestion_drop;
			}

			q->stats.forced_mark++;
			break;
	}

	ret = qdisc_enqueue(skb, child);
	if (likely(ret == NET_XMIT_SUCCESS)) {
		sch->bstats.bytes += qdisc_pkt_len(skb);
		sch->bstats.packets++;
		sch->q.qlen++;
	} else if (net_xmit_drop_count(ret)) {
		q->stats.pdrop++;
		sch->qstats.drops++;
	}
	return ret;

congestion_drop:
	qdisc_drop(skb, sch);
	return NET_XMIT_CN;
}

static int red_requeue(struct sk_buff *skb, struct Qdisc* sch)
{
	struct red_sched_data *q = qdisc_priv(sch);
	struct Qdisc *child = q->qdisc;
	int ret;

	if (red_is_idling(&q->parms))
		red_end_of_idle_period(&q->parms);

	ret = child->ops->requeue(skb, child);
	if (likely(ret == NET_XMIT_SUCCESS)) {
		sch->qstats.requeues++;
		sch->q.qlen++;
	}
	return ret;
}

static struct sk_buff * red_dequeue(struct Qdisc* sch)
{
	struct sk_buff *skb;
	struct red_sched_data *q = qdisc_priv(sch);
	struct Qdisc *child = q->qdisc;

	skb = child->dequeue(child);
	if (skb)
		sch->q.qlen--;
	else if (!red_is_idling(&q->parms))
		red_start_of_idle_period(&q->parms);

	return skb;
}

static unsigned int red_drop(struct Qdisc* sch)
{
	struct red_sched_data *q = qdisc_priv(sch);
	struct Qdisc *child = q->qdisc;
	unsigned int len;

	if (child->ops->drop && (len = child->ops->drop(child)) > 0) {
		q->stats.other++;
		sch->qstats.drops++;
		sch->q.qlen--;
		return len;
	}

	if (!red_is_idling(&q->parms))
		red_start_of_idle_period(&q->parms);

	return 0;
}

static void red_reset(struct Qdisc* sch)
{
	struct red_sched_data *q = qdisc_priv(sch);

	qdisc_reset(q->qdisc);
	sch->q.qlen = 0;
	red_restart(&q->parms);
}

static void red_destroy(struct Qdisc *sch)
{
	struct red_sched_data *q = qdisc_priv(sch);
	qdisc_destroy(q->qdisc);
}

static const struct nla_policy red_policy[TCA_RED_MAX + 1] = {
	[TCA_RED_PARMS]	= { .len = sizeof(struct tc_red_qopt) },
	[TCA_RED_STAB]	= { .len = RED_STAB_SIZE },
};

static int red_change(struct Qdisc *sch, struct nlattr *opt)
{
	struct red_sched_data *q = qdisc_priv(sch);
	struct nlattr *tb[TCA_RED_MAX + 1];
	struct tc_red_qopt *ctl;
	struct Qdisc *child = NULL;
	int err;

	if (opt == NULL)
		return -EINVAL;

	err = nla_parse_nested(tb, TCA_RED_MAX, opt, red_policy);
	if (err < 0)
		return err;

	if (tb[TCA_RED_PARMS] == NULL ||
	    tb[TCA_RED_STAB] == NULL)
		return -EINVAL;

	ctl = nla_data(tb[TCA_RED_PARMS]);

	if (ctl->limit > 0) {
		child = fifo_create_dflt(sch, &bfifo_qdisc_ops, ctl->limit);
		if (IS_ERR(child))
			return PTR_ERR(child);
	}

	sch_tree_lock(sch);
	q->flags = ctl->flags;
	q->limit = ctl->limit;
	if (child) {
		qdisc_tree_decrease_qlen(q->qdisc, q->qdisc->q.qlen);
		qdisc_destroy(xchg(&q->qdisc, child));
	}

	red_set_parms(&q->parms, ctl->qth_min, ctl->qth_max, ctl->Wlog,
				 ctl->Plog, ctl->Scell_log,
				 nla_data(tb[TCA_RED_STAB]));

	if (skb_queue_empty(&sch->q))
		red_end_of_idle_period(&q->parms);

	sch_tree_unlock(sch);
	return 0;
}

static int red_init(struct Qdisc* sch, struct nlattr *opt)
{
	struct red_sched_data *q = qdisc_priv(sch);

	q->qdisc = &noop_qdisc;
	return red_change(sch, opt);
}

static int red_dump(struct Qdisc *sch, struct sk_buff *skb)
{
	struct red_sched_data *q = qdisc_priv(sch);
	struct nlattr *opts = NULL;
	struct tc_red_qopt opt = {
		.limit		= q->limit,
		.flags		= q->flags,
		.qth_min	= q->parms.qth_min >> q->parms.Wlog,
		.qth_max	= q->parms.qth_max >> q->parms.Wlog,
		.Wlog		= q->parms.Wlog,
		.Plog		= q->parms.Plog,
		.Scell_log	= q->parms.Scell_log,
	};

	opts = nla_nest_start(skb, TCA_OPTIONS);
	if (opts == NULL)
		goto nla_put_failure;
	NLA_PUT(skb, TCA_RED_PARMS, sizeof(opt), &opt);
	return nla_nest_end(skb, opts);

nla_put_failure:
	nla_nest_cancel(skb, opts);
	return -EMSGSIZE;
}

static int red_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
{
	struct red_sched_data *q = qdisc_priv(sch);
	struct tc_red_xstats st = {
		.early	= q->stats.prob_drop + q->stats.forced_drop,
		.pdrop	= q->stats.pdrop,
		.other	= q->stats.other,
		.marked	= q->stats.prob_mark + q->stats.forced_mark,
	};

	return gnet_stats_copy_app(d, &st, sizeof(st));
}

static int red_dump_class(struct Qdisc *sch, unsigned long cl,
			  struct sk_buff *skb, struct tcmsg *tcm)
{
	struct red_sched_data *q = qdisc_priv(sch);

	if (cl != 1)
		return -ENOENT;
	tcm->tcm_handle |= TC_H_MIN(1);
	tcm->tcm_info = q->qdisc->handle;
	return 0;
}

static int red_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
		     struct Qdisc **old)
{
	struct red_sched_data *q = qdisc_priv(sch);

	if (new == NULL)
		new = &noop_qdisc;

	sch_tree_lock(sch);
	*old = xchg(&q->qdisc, new);
	qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
	qdisc_reset(*old);
	sch_tree_unlock(sch);
	return 0;
}

static struct Qdisc *red_leaf(struct Qdisc *sch, unsigned long arg)
{
	struct red_sched_data *q = qdisc_priv(sch);
	return q->qdisc;
}

static unsigned long red_get(struct Qdisc *sch, u32 classid)
{
	return 1;
}

static void red_put(struct Qdisc *sch, unsigned long arg)
{
	return;
}

static int red_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
			    struct nlattr **tca, unsigned long *arg)
{
	return -ENOSYS;
}

static int red_delete(struct Qdisc *sch, unsigned long cl)
{
	return -ENOSYS;
}

static void red_walk(struct Qdisc *sch, struct qdisc_walker *walker)
{
	if (!walker->stop) {
		if (walker->count >= walker->skip)
			if (walker->fn(sch, 1, walker) < 0) {
				walker->stop = 1;
				return;
			}
		walker->count++;
	}
}

static struct tcf_proto **red_find_tcf(struct Qdisc *sch, unsigned long cl)
{
	return NULL;
}

static const struct Qdisc_class_ops red_class_ops = {
	.graft		=	red_graft,
	.leaf		=	red_leaf,
	.get		=	red_get,
	.put		=	red_put,
	.change		=	red_change_class,
	.delete		=	red_delete,
	.walk		=	red_walk,
	.tcf_chain	=	red_find_tcf,
	.dump		=	red_dump_class,
};

static struct Qdisc_ops red_qdisc_ops __read_mostly = {
	.id		=	"red",
	.priv_size	=	sizeof(struct red_sched_data),
	.cl_ops		=	&red_class_ops,
	.enqueue	=	red_enqueue,
	.dequeue	=	red_dequeue,
	.requeue	=	red_requeue,
	.drop		=	red_drop,
	.init		=	red_init,
	.reset		=	red_reset,
	.destroy	=	red_destroy,
	.change		=	red_change,
	.dump		=	red_dump,
	.dump_stats	=	red_dump_stats,
	.owner		=	THIS_MODULE,
};

static int __init red_module_init(void)
{
	return register_qdisc(&red_qdisc_ops);
}

static void __exit red_module_exit(void)
{
	unregister_qdisc(&red_qdisc_ops);
}

module_init(red_module_init)
module_exit(red_module_exit)

MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* net/sched/sch_red.c Random Early Detection queue.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation; either version
	7	* 2 of the License, or (at your option) any later version.
	8	*
	9	* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
	10	*
	11	* Changes:
dba051f3	12	* J Hadi Salim 980914: computation fixes
1da177e4	13	* Alexey Makarenko <makar@phoenix.kharkov.ua> 990814: qave on idle link was calculated incorrectly.
dba051f3	14	* J Hadi Salim 980816: ECN support
1da177e4 LT	15	*/
1da177e4 LT	16
1da177e4	17	#include <linux/module.h>
1da177e4 LT	18	#include <linux/types.h>
1da177e4 LT	19	#include <linux/kernel.h>
1da177e4	20	#include <linux/skbuff.h>
1da177e4 LT	21	#include <net/pkt_sched.h>
1da177e4 LT	22	#include <net/inet_ecn.h>
6b31b28a	23	#include <net/red.h>
1da177e4 LT	24
1da177e4 LT	25
6b31b28a	26	/* Parameters, settable by user:
1da177e4 LT	27	-----------------------------
	28
	29	limit - bytes (must be > qth_max + burst)
	30
	31	Hard limit on queue length, should be chosen >qth_max
	32	to allow packet bursts. This parameter does not
	33	affect the algorithms behaviour and can be chosen
	34	arbitrarily high (well, less than ram size)
	35	Really, this limit will never be reached
	36	if RED works correctly.
1da177e4 LT	37	*/
	38
	39	struct red_sched_data
	40	{
6b31b28a TG	41	u32 limit; /* HARD maximal queue length */
	42	unsigned char flags;
	43	struct red_parms parms;
	44	struct red_stats stats;
f38c39d6	45	struct Qdisc *qdisc;
1da177e4 LT	46	};
1da177e4 LT	47
6b31b28a	48	static inline int red_use_ecn(struct red_sched_data *q)
1da177e4	49	{
6b31b28a	50	return q->flags & TC_RED_ECN;
1da177e4 LT	51	}
1da177e4 LT	52
bdc450a0 TG	53	static inline int red_use_harddrop(struct red_sched_data *q)
	54	{
	55	return q->flags & TC_RED_HARDDROP;
	56	}
	57
dba051f3	58	static int red_enqueue(struct sk_buff skb, struct Qdisc sch)
1da177e4 LT	59	{
1da177e4 LT	60	struct red_sched_data *q = qdisc_priv(sch);
f38c39d6 PM	61	struct Qdisc *child = q->qdisc;
f38c39d6 PM	62	int ret;
1da177e4	63
f38c39d6	64	q->parms.qavg = red_calc_qavg(&q->parms, child->qstats.backlog);
1da177e4	65
6b31b28a TG	66	if (red_is_idling(&q->parms))
6b31b28a TG	67	red_end_of_idle_period(&q->parms);
1da177e4	68
6b31b28a TG	69	switch (red_action(&q->parms, q->parms.qavg)) {
	70	case RED_DONT_MARK:
	71	break;
1da177e4	72
6b31b28a TG	73	case RED_PROB_MARK:
	74	sch->qstats.overlimits++;
	75	if (!red_use_ecn(q) \|\| !INET_ECN_set_ce(skb)) {
	76	q->stats.prob_drop++;
	77	goto congestion_drop;
	78	}
1da177e4	79
6b31b28a TG	80	q->stats.prob_mark++;
	81	break;
	82
	83	case RED_HARD_MARK:
	84	sch->qstats.overlimits++;
bdc450a0 TG	85	if (red_use_harddrop(q) \|\| !red_use_ecn(q) \|\|
bdc450a0 TG	86	!INET_ECN_set_ce(skb)) {
6b31b28a TG	87	q->stats.forced_drop++;
	88	goto congestion_drop;
	89	}
	90
	91	q->stats.forced_mark++;
	92	break;
1da177e4 LT	93	}
1da177e4 LT	94
5f86173b	95	ret = qdisc_enqueue(skb, child);
f38c39d6	96	if (likely(ret == NET_XMIT_SUCCESS)) {
0abf77e5	97	sch->bstats.bytes += qdisc_pkt_len(skb);
f38c39d6 PM	98	sch->bstats.packets++;
f38c39d6 PM	99	sch->q.qlen++;
378a2f09	100	} else if (net_xmit_drop_count(ret)) {
f38c39d6 PM	101	q->stats.pdrop++;
	102	sch->qstats.drops++;
	103	}
	104	return ret;
6b31b28a TG	105
6b31b28a TG	106	congestion_drop:
9e178ff2	107	qdisc_drop(skb, sch);
1da177e4 LT	108	return NET_XMIT_CN;
	109	}
	110
dba051f3	111	static int red_requeue(struct sk_buff skb, struct Qdisc sch)
1da177e4 LT	112	{
1da177e4 LT	113	struct red_sched_data *q = qdisc_priv(sch);
f38c39d6 PM	114	struct Qdisc *child = q->qdisc;
f38c39d6 PM	115	int ret;
1da177e4	116
6b31b28a TG	117	if (red_is_idling(&q->parms))
6b31b28a TG	118	red_end_of_idle_period(&q->parms);
1da177e4	119
f38c39d6 PM	120	ret = child->ops->requeue(skb, child);
	121	if (likely(ret == NET_XMIT_SUCCESS)) {
	122	sch->qstats.requeues++;
	123	sch->q.qlen++;
	124	}
	125	return ret;
1da177e4 LT	126	}
1da177e4 LT	127
dba051f3	128	static struct sk_buff * red_dequeue(struct Qdisc* sch)
1da177e4 LT	129	{
	130	struct sk_buff *skb;
	131	struct red_sched_data *q = qdisc_priv(sch);
f38c39d6	132	struct Qdisc *child = q->qdisc;
1da177e4	133
f38c39d6 PM	134	skb = child->dequeue(child);
	135	if (skb)
	136	sch->q.qlen--;
	137	else if (!red_is_idling(&q->parms))
9e178ff2 TG	138	red_start_of_idle_period(&q->parms);
	139
	140	return skb;
1da177e4 LT	141	}
	142
	143	static unsigned int red_drop(struct Qdisc* sch)
	144	{
1da177e4	145	struct red_sched_data *q = qdisc_priv(sch);
f38c39d6 PM	146	struct Qdisc *child = q->qdisc;
f38c39d6 PM	147	unsigned int len;
1da177e4	148
f38c39d6	149	if (child->ops->drop && (len = child->ops->drop(child)) > 0) {
6b31b28a	150	q->stats.other++;
f38c39d6 PM	151	sch->qstats.drops++;
f38c39d6 PM	152	sch->q.qlen--;
1da177e4 LT	153	return len;
1da177e4 LT	154	}
6b31b28a	155
6a1b63d4 TG	156	if (!red_is_idling(&q->parms))
	157	red_start_of_idle_period(&q->parms);
	158
1da177e4 LT	159	return 0;
	160	}
	161
	162	static void red_reset(struct Qdisc* sch)
	163	{
	164	struct red_sched_data *q = qdisc_priv(sch);
	165
f38c39d6 PM	166	qdisc_reset(q->qdisc);
f38c39d6 PM	167	sch->q.qlen = 0;
6b31b28a	168	red_restart(&q->parms);
1da177e4 LT	169	}
1da177e4 LT	170
f38c39d6 PM	171	static void red_destroy(struct Qdisc *sch)
	172	{
	173	struct red_sched_data *q = qdisc_priv(sch);
	174	qdisc_destroy(q->qdisc);
	175	}
	176
27a3421e PM	177	static const struct nla_policy red_policy[TCA_RED_MAX + 1] = {
	178	[TCA_RED_PARMS] = { .len = sizeof(struct tc_red_qopt) },
	179	[TCA_RED_STAB] = { .len = RED_STAB_SIZE },
	180	};
	181
1e90474c	182	static int red_change(struct Qdisc sch, struct nlattr opt)
1da177e4 LT	183	{
1da177e4 LT	184	struct red_sched_data *q = qdisc_priv(sch);
1e90474c	185	struct nlattr *tb[TCA_RED_MAX + 1];
1da177e4	186	struct tc_red_qopt *ctl;
f38c39d6	187	struct Qdisc *child = NULL;
cee63723	188	int err;
1da177e4	189
cee63723	190	if (opt == NULL)
dba051f3 TG	191	return -EINVAL;
dba051f3 TG	192
27a3421e	193	err = nla_parse_nested(tb, TCA_RED_MAX, opt, red_policy);
cee63723 PM	194	if (err < 0)
	195	return err;
	196
1e90474c	197	if (tb[TCA_RED_PARMS] == NULL \|\|
27a3421e	198	tb[TCA_RED_STAB] == NULL)
1da177e4 LT	199	return -EINVAL;
1da177e4 LT	200
1e90474c	201	ctl = nla_data(tb[TCA_RED_PARMS]);
1da177e4	202
f38c39d6	203	if (ctl->limit > 0) {
fb0305ce PM	204	child = fifo_create_dflt(sch, &bfifo_qdisc_ops, ctl->limit);
	205	if (IS_ERR(child))
	206	return PTR_ERR(child);
f38c39d6 PM	207	}
f38c39d6 PM	208
1da177e4 LT	209	sch_tree_lock(sch);
1da177e4 LT	210	q->flags = ctl->flags;
1da177e4	211	q->limit = ctl->limit;
5e50da01 PM	212	if (child) {
5e50da01 PM	213	qdisc_tree_decrease_qlen(q->qdisc, q->qdisc->q.qlen);
f38c39d6	214	qdisc_destroy(xchg(&q->qdisc, child));
5e50da01	215	}
1da177e4	216
6b31b28a TG	217	red_set_parms(&q->parms, ctl->qth_min, ctl->qth_max, ctl->Wlog,
6b31b28a TG	218	ctl->Plog, ctl->Scell_log,
1e90474c	219	nla_data(tb[TCA_RED_STAB]));
6b31b28a	220
b03efcfb	221	if (skb_queue_empty(&sch->q))
6b31b28a	222	red_end_of_idle_period(&q->parms);
dba051f3	223
1da177e4 LT	224	sch_tree_unlock(sch);
	225	return 0;
	226	}
	227
1e90474c	228	static int red_init(struct Qdisc* sch, struct nlattr *opt)
1da177e4	229	{
f38c39d6 PM	230	struct red_sched_data *q = qdisc_priv(sch);
	231
	232	q->qdisc = &noop_qdisc;
1da177e4 LT	233	return red_change(sch, opt);
	234	}
	235
	236	static int red_dump(struct Qdisc sch, struct sk_buff skb)
	237	{
	238	struct red_sched_data *q = qdisc_priv(sch);
1e90474c	239	struct nlattr *opts = NULL;
6b31b28a TG	240	struct tc_red_qopt opt = {
	241	.limit = q->limit,
	242	.flags = q->flags,
	243	.qth_min = q->parms.qth_min >> q->parms.Wlog,
	244	.qth_max = q->parms.qth_max >> q->parms.Wlog,
	245	.Wlog = q->parms.Wlog,
	246	.Plog = q->parms.Plog,
	247	.Scell_log = q->parms.Scell_log,
	248	};
1da177e4	249
1e90474c PM	250	opts = nla_nest_start(skb, TCA_OPTIONS);
	251	if (opts == NULL)
	252	goto nla_put_failure;
	253	NLA_PUT(skb, TCA_RED_PARMS, sizeof(opt), &opt);
	254	return nla_nest_end(skb, opts);
1da177e4	255
1e90474c	256	nla_put_failure:
bc3ed28c TG	257	nla_nest_cancel(skb, opts);
bc3ed28c TG	258	return -EMSGSIZE;
1da177e4 LT	259	}
	260
	261	static int red_dump_stats(struct Qdisc sch, struct gnet_dump d)
	262	{
	263	struct red_sched_data *q = qdisc_priv(sch);
6b31b28a TG	264	struct tc_red_xstats st = {
	265	.early = q->stats.prob_drop + q->stats.forced_drop,
	266	.pdrop = q->stats.pdrop,
	267	.other = q->stats.other,
	268	.marked = q->stats.prob_mark + q->stats.forced_mark,
	269	};
	270
	271	return gnet_stats_copy_app(d, &st, sizeof(st));
1da177e4 LT	272	}
1da177e4 LT	273
f38c39d6 PM	274	static int red_dump_class(struct Qdisc *sch, unsigned long cl,
	275	struct sk_buff skb, struct tcmsg tcm)
	276	{
	277	struct red_sched_data *q = qdisc_priv(sch);
	278
	279	if (cl != 1)
	280	return -ENOENT;
	281	tcm->tcm_handle \|= TC_H_MIN(1);
	282	tcm->tcm_info = q->qdisc->handle;
	283	return 0;
	284	}
	285
	286	static int red_graft(struct Qdisc sch, unsigned long arg, struct Qdisc new,
	287	struct Qdisc **old)
	288	{
	289	struct red_sched_data *q = qdisc_priv(sch);
	290
	291	if (new == NULL)
	292	new = &noop_qdisc;
	293
	294	sch_tree_lock(sch);
	295	*old = xchg(&q->qdisc, new);
5e50da01	296	qdisc_tree_decrease_qlen(old, (old)->q.qlen);
f38c39d6	297	qdisc_reset(*old);
f38c39d6 PM	298	sch_tree_unlock(sch);
	299	return 0;
	300	}
	301
	302	static struct Qdisc red_leaf(struct Qdisc sch, unsigned long arg)
	303	{
	304	struct red_sched_data *q = qdisc_priv(sch);
	305	return q->qdisc;
	306	}
	307
	308	static unsigned long red_get(struct Qdisc *sch, u32 classid)
	309	{
	310	return 1;
	311	}
	312
	313	static void red_put(struct Qdisc *sch, unsigned long arg)
	314	{
	315	return;
	316	}
	317
	318	static int red_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
1e90474c	319	struct nlattr *tca, unsigned long arg)
f38c39d6 PM	320	{
	321	return -ENOSYS;
	322	}
	323
	324	static int red_delete(struct Qdisc *sch, unsigned long cl)
	325	{
	326	return -ENOSYS;
	327	}
	328
	329	static void red_walk(struct Qdisc sch, struct qdisc_walker walker)
	330	{
	331	if (!walker->stop) {
	332	if (walker->count >= walker->skip)
	333	if (walker->fn(sch, 1, walker) < 0) {
	334	walker->stop = 1;
	335	return;
	336	}
	337	walker->count++;
	338	}
	339	}
	340
	341	static struct tcf_proto *red_find_tcf(struct Qdisc sch, unsigned long cl)
	342	{
	343	return NULL;
	344	}
	345
20fea08b	346	static const struct Qdisc_class_ops red_class_ops = {
f38c39d6 PM	347	.graft = red_graft,
	348	.leaf = red_leaf,
	349	.get = red_get,
	350	.put = red_put,
	351	.change = red_change_class,
	352	.delete = red_delete,
	353	.walk = red_walk,
	354	.tcf_chain = red_find_tcf,
	355	.dump = red_dump_class,
	356	};
	357
20fea08b	358	static struct Qdisc_ops red_qdisc_ops __read_mostly = {
1da177e4 LT	359	.id = "red",
1da177e4 LT	360	.priv_size = sizeof(struct red_sched_data),
f38c39d6	361	.cl_ops = &red_class_ops,
1da177e4 LT	362	.enqueue = red_enqueue,
	363	.dequeue = red_dequeue,
	364	.requeue = red_requeue,
	365	.drop = red_drop,
	366	.init = red_init,
	367	.reset = red_reset,
f38c39d6	368	.destroy = red_destroy,
1da177e4 LT	369	.change = red_change,
	370	.dump = red_dump,
	371	.dump_stats = red_dump_stats,
	372	.owner = THIS_MODULE,
	373	};
	374
	375	static int __init red_module_init(void)
	376	{
	377	return register_qdisc(&red_qdisc_ops);
	378	}
dba051f3 TG	379
dba051f3 TG	380	static void __exit red_module_exit(void)
1da177e4 LT	381	{
	382	unregister_qdisc(&red_qdisc_ops);
	383	}
dba051f3	384
1da177e4 LT	385	module_init(red_module_init)
1da177e4 LT	386	module_exit(red_module_exit)
dba051f3	387
1da177e4	388	MODULE_LICENSE("GPL");