[linux.git] / net / sched / sch_drr.c

/*
 * net/sched/sch_drr.c         Deficit Round Robin scheduler
 *
 * Copyright (c) 2008 Patrick McHardy <[email protected]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/pkt_sched.h>
#include <net/sch_generic.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>

struct drr_class {
	struct Qdisc_class_common	common;
	unsigned int			refcnt;
	unsigned int			filter_cnt;

	struct gnet_stats_basic_packed		bstats;
	struct gnet_stats_queue		qstats;
	struct gnet_stats_rate_est	rate_est;
	struct list_head		alist;
	struct Qdisc			*qdisc;

	u32				quantum;
	u32				deficit;
};

struct drr_sched {
	struct list_head		active;
	struct tcf_proto		*filter_list;
	struct Qdisc_class_hash		clhash;
};

static struct drr_class *drr_find_class(struct Qdisc *sch, u32 classid)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct Qdisc_class_common *clc;

	clc = qdisc_class_find(&q->clhash, classid);
	if (clc == NULL)
		return NULL;
	return container_of(clc, struct drr_class, common);
}

static void drr_purge_queue(struct drr_class *cl)
{
	unsigned int len = cl->qdisc->q.qlen;

	qdisc_reset(cl->qdisc);
	qdisc_tree_decrease_qlen(cl->qdisc, len);
}

static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
	[TCA_DRR_QUANTUM]	= { .type = NLA_U32 },
};

static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
			    struct nlattr **tca, unsigned long *arg)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl = (struct drr_class *)*arg;
	struct nlattr *opt = tca[TCA_OPTIONS];
	struct nlattr *tb[TCA_DRR_MAX + 1];
	u32 quantum;
	int err;

	if (!opt)
		return -EINVAL;

	err = nla_parse_nested(tb, TCA_DRR_MAX, opt, drr_policy);
	if (err < 0)
		return err;

	if (tb[TCA_DRR_QUANTUM]) {
		quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
		if (quantum == 0)
			return -EINVAL;
	} else
		quantum = psched_mtu(qdisc_dev(sch));

	if (cl != NULL) {
		if (tca[TCA_RATE]) {
			err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
						    qdisc_root_sleeping_lock(sch),
						    tca[TCA_RATE]);
			if (err)
				return err;
		}

		sch_tree_lock(sch);
		if (tb[TCA_DRR_QUANTUM])
			cl->quantum = quantum;
		sch_tree_unlock(sch);

		return 0;
	}

	cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
	if (cl == NULL)
		return -ENOBUFS;

	cl->refcnt	   = 1;
	cl->common.classid = classid;
	cl->quantum	   = quantum;
	cl->qdisc	   = qdisc_create_dflt(sch->dev_queue,
					       &pfifo_qdisc_ops, classid);
	if (cl->qdisc == NULL)
		cl->qdisc = &noop_qdisc;

	if (tca[TCA_RATE]) {
		err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
					    qdisc_root_sleeping_lock(sch),
					    tca[TCA_RATE]);
		if (err) {
			qdisc_destroy(cl->qdisc);
			kfree(cl);
			return err;
		}
	}

	sch_tree_lock(sch);
	qdisc_class_hash_insert(&q->clhash, &cl->common);
	sch_tree_unlock(sch);

	qdisc_class_hash_grow(sch, &q->clhash);

	*arg = (unsigned long)cl;
	return 0;
}

static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl)
{
	gen_kill_estimator(&cl->bstats, &cl->rate_est);
	qdisc_destroy(cl->qdisc);
	kfree(cl);
}

static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl = (struct drr_class *)arg;

	if (cl->filter_cnt > 0)
		return -EBUSY;

	sch_tree_lock(sch);

	drr_purge_queue(cl);
	qdisc_class_hash_remove(&q->clhash, &cl->common);

	BUG_ON(--cl->refcnt == 0);
	/*
	 * This shouldn't happen: we "hold" one cops->get() when called
	 * from tc_ctl_tclass; the destroy method is done from cops->put().
	 */

	sch_tree_unlock(sch);
	return 0;
}

static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
{
	struct drr_class *cl = drr_find_class(sch, classid);

	if (cl != NULL)
		cl->refcnt++;

	return (unsigned long)cl;
}

static void drr_put_class(struct Qdisc *sch, unsigned long arg)
{
	struct drr_class *cl = (struct drr_class *)arg;

	if (--cl->refcnt == 0)
		drr_destroy_class(sch, cl);
}

static struct tcf_proto **drr_tcf_chain(struct Qdisc *sch, unsigned long cl)
{
	struct drr_sched *q = qdisc_priv(sch);

	if (cl)
		return NULL;

	return &q->filter_list;
}

static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
				  u32 classid)
{
	struct drr_class *cl = drr_find_class(sch, classid);

	if (cl != NULL)
		cl->filter_cnt++;

	return (unsigned long)cl;
}

static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
{
	struct drr_class *cl = (struct drr_class *)arg;

	cl->filter_cnt--;
}

static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
			   struct Qdisc *new, struct Qdisc **old)
{
	struct drr_class *cl = (struct drr_class *)arg;

	if (new == NULL) {
		new = qdisc_create_dflt(sch->dev_queue,
					&pfifo_qdisc_ops, cl->common.classid);
		if (new == NULL)
			new = &noop_qdisc;
	}

	sch_tree_lock(sch);
	drr_purge_queue(cl);
	*old = cl->qdisc;
	cl->qdisc = new;
	sch_tree_unlock(sch);
	return 0;
}

static struct Qdisc *drr_class_leaf(struct Qdisc *sch, unsigned long arg)
{
	struct drr_class *cl = (struct drr_class *)arg;

	return cl->qdisc;
}

static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
{
	struct drr_class *cl = (struct drr_class *)arg;

	if (cl->qdisc->q.qlen == 0)
		list_del(&cl->alist);
}

static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
			  struct sk_buff *skb, struct tcmsg *tcm)
{
	struct drr_class *cl = (struct drr_class *)arg;
	struct nlattr *nest;

	tcm->tcm_parent	= TC_H_ROOT;
	tcm->tcm_handle	= cl->common.classid;
	tcm->tcm_info	= cl->qdisc->handle;

	nest = nla_nest_start(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;
	NLA_PUT_U32(skb, TCA_DRR_QUANTUM, cl->quantum);
	return nla_nest_end(skb, nest);

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

static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
				struct gnet_dump *d)
{
	struct drr_class *cl = (struct drr_class *)arg;
	struct tc_drr_stats xstats;

	memset(&xstats, 0, sizeof(xstats));
	if (cl->qdisc->q.qlen) {
		xstats.deficit = cl->deficit;
		cl->qdisc->qstats.qlen = cl->qdisc->q.qlen;
	}

	if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
	    gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
	    gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
		return -1;

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

static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	struct hlist_node *n;
	unsigned int i;

	if (arg->stop)
		return;

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
			if (arg->count < arg->skip) {
				arg->count++;
				continue;
			}
			if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
				arg->stop = 1;
				return;
			}
			arg->count++;
		}
	}
}

static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
				      int *qerr)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	struct tcf_result res;
	int result;

	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
		cl = drr_find_class(sch, skb->priority);
		if (cl != NULL)
			return cl;
	}

	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
	result = tc_classify(skb, q->filter_list, &res);
	if (result >= 0) {
#ifdef CONFIG_NET_CLS_ACT
		switch (result) {
		case TC_ACT_QUEUED:
		case TC_ACT_STOLEN:
			*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
		case TC_ACT_SHOT:
			return NULL;
		}
#endif
		cl = (struct drr_class *)res.class;
		if (cl == NULL)
			cl = drr_find_class(sch, res.classid);
		return cl;
	}
	return NULL;
}

static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	int err;

	cl = drr_classify(skb, sch, &err);
	if (cl == NULL) {
		if (err & __NET_XMIT_BYPASS)
			sch->qstats.drops++;
		kfree_skb(skb);
		return err;
	}

	err = qdisc_enqueue(skb, cl->qdisc);
	if (unlikely(err != NET_XMIT_SUCCESS)) {
		if (net_xmit_drop_count(err)) {
			cl->qstats.drops++;
			sch->qstats.drops++;
		}
		return err;
	}

	if (cl->qdisc->q.qlen == 1) {
		list_add_tail(&cl->alist, &q->active);
		cl->deficit = cl->quantum;
	}

	bstats_update(&cl->bstats, skb);

	sch->q.qlen++;
	return err;
}

static struct sk_buff *drr_dequeue(struct Qdisc *sch)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	struct sk_buff *skb;
	unsigned int len;

	if (list_empty(&q->active))
		goto out;
	while (1) {
		cl = list_first_entry(&q->active, struct drr_class, alist);
		skb = cl->qdisc->ops->peek(cl->qdisc);
		if (skb == NULL)
			goto out;

		len = qdisc_pkt_len(skb);
		if (len <= cl->deficit) {
			cl->deficit -= len;
			skb = qdisc_dequeue_peeked(cl->qdisc);
			if (cl->qdisc->q.qlen == 0)
				list_del(&cl->alist);
			qdisc_bstats_update(sch, skb);
			sch->q.qlen--;
			return skb;
		}

		cl->deficit += cl->quantum;
		list_move_tail(&cl->alist, &q->active);
	}
out:
	return NULL;
}

static unsigned int drr_drop(struct Qdisc *sch)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	unsigned int len;

	list_for_each_entry(cl, &q->active, alist) {
		if (cl->qdisc->ops->drop) {
			len = cl->qdisc->ops->drop(cl->qdisc);
			if (len > 0) {
				sch->q.qlen--;
				if (cl->qdisc->q.qlen == 0)
					list_del(&cl->alist);
				return len;
			}
		}
	}
	return 0;
}

static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
{
	struct drr_sched *q = qdisc_priv(sch);
	int err;

	err = qdisc_class_hash_init(&q->clhash);
	if (err < 0)
		return err;
	INIT_LIST_HEAD(&q->active);
	return 0;
}

static void drr_reset_qdisc(struct Qdisc *sch)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	struct hlist_node *n;
	unsigned int i;

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
			if (cl->qdisc->q.qlen)
				list_del(&cl->alist);
			qdisc_reset(cl->qdisc);
		}
	}
	sch->q.qlen = 0;
}

static void drr_destroy_qdisc(struct Qdisc *sch)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	struct hlist_node *n, *next;
	unsigned int i;

	tcf_destroy_chain(&q->filter_list);

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry_safe(cl, n, next, &q->clhash.hash[i],
					  common.hnode)
			drr_destroy_class(sch, cl);
	}
	qdisc_class_hash_destroy(&q->clhash);
}

static const struct Qdisc_class_ops drr_class_ops = {
	.change		= drr_change_class,
	.delete		= drr_delete_class,
	.get		= drr_get_class,
	.put		= drr_put_class,
	.tcf_chain	= drr_tcf_chain,
	.bind_tcf	= drr_bind_tcf,
	.unbind_tcf	= drr_unbind_tcf,
	.graft		= drr_graft_class,
	.leaf		= drr_class_leaf,
	.qlen_notify	= drr_qlen_notify,
	.dump		= drr_dump_class,
	.dump_stats	= drr_dump_class_stats,
	.walk		= drr_walk,
};

static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
	.cl_ops		= &drr_class_ops,
	.id		= "drr",
	.priv_size	= sizeof(struct drr_sched),
	.enqueue	= drr_enqueue,
	.dequeue	= drr_dequeue,
	.peek		= qdisc_peek_dequeued,
	.drop		= drr_drop,
	.init		= drr_init_qdisc,
	.reset		= drr_reset_qdisc,
	.destroy	= drr_destroy_qdisc,
	.owner		= THIS_MODULE,
};

static int __init drr_init(void)
{
	return register_qdisc(&drr_qdisc_ops);
}

static void __exit drr_exit(void)
{
	unregister_qdisc(&drr_qdisc_ops);
}

module_init(drr_init);
module_exit(drr_exit);
MODULE_LICENSE("GPL");
Commit	Line	Data
13d2a1d2 PM	1	/*
	2	* net/sched/sch_drr.c Deficit Round Robin scheduler
	3	*
	4	* Copyright (c) 2008 Patrick McHardy <[email protected]>
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* version 2 as published by the Free Software Foundation.
	9	*/
	10
	11	#include <linux/module.h>
5a0e3ad6	12	#include <linux/slab.h>
13d2a1d2 PM	13	#include <linux/init.h>
	14	#include <linux/errno.h>
	15	#include <linux/netdevice.h>
	16	#include <linux/pkt_sched.h>
	17	#include <net/sch_generic.h>
	18	#include <net/pkt_sched.h>
	19	#include <net/pkt_cls.h>
	20
	21	struct drr_class {
	22	struct Qdisc_class_common common;
	23	unsigned int refcnt;
	24	unsigned int filter_cnt;
	25
c1a8f1f1	26	struct gnet_stats_basic_packed bstats;
13d2a1d2 PM	27	struct gnet_stats_queue qstats;
	28	struct gnet_stats_rate_est rate_est;
	29	struct list_head alist;
	30	struct Qdisc *qdisc;
	31
	32	u32 quantum;
	33	u32 deficit;
	34	};
	35
	36	struct drr_sched {
	37	struct list_head active;
	38	struct tcf_proto *filter_list;
	39	struct Qdisc_class_hash clhash;
	40	};
	41
	42	static struct drr_class drr_find_class(struct Qdisc sch, u32 classid)
	43	{
	44	struct drr_sched *q = qdisc_priv(sch);
	45	struct Qdisc_class_common *clc;
	46
	47	clc = qdisc_class_find(&q->clhash, classid);
	48	if (clc == NULL)
	49	return NULL;
	50	return container_of(clc, struct drr_class, common);
	51	}
	52
	53	static void drr_purge_queue(struct drr_class *cl)
	54	{
	55	unsigned int len = cl->qdisc->q.qlen;
	56
	57	qdisc_reset(cl->qdisc);
	58	qdisc_tree_decrease_qlen(cl->qdisc, len);
	59	}
	60
	61	static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
	62	[TCA_DRR_QUANTUM] = { .type = NLA_U32 },
	63	};
	64
	65	static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
	66	struct nlattr *tca, unsigned long arg)
	67	{
	68	struct drr_sched *q = qdisc_priv(sch);
	69	struct drr_class cl = (struct drr_class )*arg;
1844f747	70	struct nlattr *opt = tca[TCA_OPTIONS];
13d2a1d2 PM	71	struct nlattr *tb[TCA_DRR_MAX + 1];
	72	u32 quantum;
	73	int err;
	74
1844f747 JP	75	if (!opt)
	76	return -EINVAL;
	77
	78	err = nla_parse_nested(tb, TCA_DRR_MAX, opt, drr_policy);
13d2a1d2 PM	79	if (err < 0)
	80	return err;
	81
	82	if (tb[TCA_DRR_QUANTUM]) {
	83	quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
	84	if (quantum == 0)
	85	return -EINVAL;
	86	} else
	87	quantum = psched_mtu(qdisc_dev(sch));
	88
	89	if (cl != NULL) {
71bcb09a SH	90	if (tca[TCA_RATE]) {
	91	err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
	92	qdisc_root_sleeping_lock(sch),
	93	tca[TCA_RATE]);
	94	if (err)
	95	return err;
	96	}
	97
13d2a1d2 PM	98	sch_tree_lock(sch);
	99	if (tb[TCA_DRR_QUANTUM])
	100	cl->quantum = quantum;
	101	sch_tree_unlock(sch);
	102
13d2a1d2 PM	103	return 0;
	104	}
	105
	106	cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
	107	if (cl == NULL)
	108	return -ENOBUFS;
	109
	110	cl->refcnt = 1;
	111	cl->common.classid = classid;
	112	cl->quantum = quantum;
3511c913	113	cl->qdisc = qdisc_create_dflt(sch->dev_queue,
13d2a1d2 PM	114	&pfifo_qdisc_ops, classid);
	115	if (cl->qdisc == NULL)
	116	cl->qdisc = &noop_qdisc;
	117
71bcb09a SH	118	if (tca[TCA_RATE]) {
	119	err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
	120	qdisc_root_sleeping_lock(sch),
	121	tca[TCA_RATE]);
	122	if (err) {
	123	qdisc_destroy(cl->qdisc);
	124	kfree(cl);
	125	return err;
	126	}
	127	}
13d2a1d2 PM	128
	129	sch_tree_lock(sch);
	130	qdisc_class_hash_insert(&q->clhash, &cl->common);
	131	sch_tree_unlock(sch);
	132
	133	qdisc_class_hash_grow(sch, &q->clhash);
	134
	135	*arg = (unsigned long)cl;
	136	return 0;
	137	}
	138
	139	static void drr_destroy_class(struct Qdisc sch, struct drr_class cl)
	140	{
	141	gen_kill_estimator(&cl->bstats, &cl->rate_est);
	142	qdisc_destroy(cl->qdisc);
	143	kfree(cl);
	144	}
	145
	146	static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
	147	{
	148	struct drr_sched *q = qdisc_priv(sch);
	149	struct drr_class cl = (struct drr_class )arg;
	150
	151	if (cl->filter_cnt > 0)
	152	return -EBUSY;
	153
	154	sch_tree_lock(sch);
	155
	156	drr_purge_queue(cl);
	157	qdisc_class_hash_remove(&q->clhash, &cl->common);
	158
7cd0a638 JP	159	BUG_ON(--cl->refcnt == 0);
	160	/*
	161	* This shouldn't happen: we "hold" one cops->get() when called
	162	* from tc_ctl_tclass; the destroy method is done from cops->put().
	163	*/
13d2a1d2 PM	164
	165	sch_tree_unlock(sch);
	166	return 0;
	167	}
	168
	169	static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
	170	{
	171	struct drr_class *cl = drr_find_class(sch, classid);
	172
	173	if (cl != NULL)
	174	cl->refcnt++;
	175
	176	return (unsigned long)cl;
	177	}
	178
	179	static void drr_put_class(struct Qdisc *sch, unsigned long arg)
	180	{
	181	struct drr_class cl = (struct drr_class )arg;
	182
	183	if (--cl->refcnt == 0)
	184	drr_destroy_class(sch, cl);
	185	}
	186
	187	static struct tcf_proto *drr_tcf_chain(struct Qdisc sch, unsigned long cl)
	188	{
	189	struct drr_sched *q = qdisc_priv(sch);
	190
	191	if (cl)
	192	return NULL;
	193
	194	return &q->filter_list;
	195	}
	196
	197	static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
	198	u32 classid)
	199	{
	200	struct drr_class *cl = drr_find_class(sch, classid);
	201
	202	if (cl != NULL)
	203	cl->filter_cnt++;
	204
	205	return (unsigned long)cl;
	206	}
	207
	208	static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
	209	{
	210	struct drr_class cl = (struct drr_class )arg;
	211
	212	cl->filter_cnt--;
	213	}
	214
	215	static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
	216	struct Qdisc new, struct Qdisc *old)
	217	{
	218	struct drr_class cl = (struct drr_class )arg;
	219
	220	if (new == NULL) {
3511c913	221	new = qdisc_create_dflt(sch->dev_queue,
13d2a1d2 PM	222	&pfifo_qdisc_ops, cl->common.classid);
	223	if (new == NULL)
	224	new = &noop_qdisc;
	225	}
	226
	227	sch_tree_lock(sch);
	228	drr_purge_queue(cl);
b94c8afc PM	229	*old = cl->qdisc;
b94c8afc PM	230	cl->qdisc = new;
13d2a1d2 PM	231	sch_tree_unlock(sch);
	232	return 0;
	233	}
	234
	235	static struct Qdisc drr_class_leaf(struct Qdisc sch, unsigned long arg)
	236	{
	237	struct drr_class cl = (struct drr_class )arg;
	238
	239	return cl->qdisc;
	240	}
	241
	242	static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
	243	{
	244	struct drr_class cl = (struct drr_class )arg;
	245
	246	if (cl->qdisc->q.qlen == 0)
	247	list_del(&cl->alist);
	248	}
	249
	250	static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
	251	struct sk_buff skb, struct tcmsg tcm)
	252	{
	253	struct drr_class cl = (struct drr_class )arg;
	254	struct nlattr *nest;
	255
	256	tcm->tcm_parent = TC_H_ROOT;
	257	tcm->tcm_handle = cl->common.classid;
	258	tcm->tcm_info = cl->qdisc->handle;
	259
	260	nest = nla_nest_start(skb, TCA_OPTIONS);
	261	if (nest == NULL)
	262	goto nla_put_failure;
	263	NLA_PUT_U32(skb, TCA_DRR_QUANTUM, cl->quantum);
	264	return nla_nest_end(skb, nest);
	265
	266	nla_put_failure:
	267	nla_nest_cancel(skb, nest);
	268	return -EMSGSIZE;
	269	}
	270
	271	static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
	272	struct gnet_dump *d)
	273	{
	274	struct drr_class cl = (struct drr_class )arg;
	275	struct tc_drr_stats xstats;
	276
	277	memset(&xstats, 0, sizeof(xstats));
a19d2158	278	if (cl->qdisc->q.qlen) {
13d2a1d2	279	xstats.deficit = cl->deficit;
a19d2158 JP	280	cl->qdisc->qstats.qlen = cl->qdisc->q.qlen;
a19d2158 JP	281	}
13d2a1d2 PM	282
13d2a1d2 PM	283	if (gnet_stats_copy_basic(d, &cl->bstats) < 0 \|\|
d250a5f9	284	gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 \|\|
13d2a1d2 PM	285	gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
	286	return -1;
	287
	288	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
	289	}
	290
	291	static void drr_walk(struct Qdisc sch, struct qdisc_walker arg)
	292	{
	293	struct drr_sched *q = qdisc_priv(sch);
	294	struct drr_class *cl;
	295	struct hlist_node *n;
	296	unsigned int i;
	297
	298	if (arg->stop)
	299	return;
	300
	301	for (i = 0; i < q->clhash.hashsize; i++) {
	302	hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
	303	if (arg->count < arg->skip) {
	304	arg->count++;
	305	continue;
	306	}
	307	if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
	308	arg->stop = 1;
	309	return;
	310	}
	311	arg->count++;
	312	}
	313	}
	314	}
	315
	316	static struct drr_class drr_classify(struct sk_buff skb, struct Qdisc *sch,
	317	int *qerr)
	318	{
	319	struct drr_sched *q = qdisc_priv(sch);
	320	struct drr_class *cl;
	321	struct tcf_result res;
	322	int result;
	323
	324	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
	325	cl = drr_find_class(sch, skb->priority);
	326	if (cl != NULL)
	327	return cl;
	328	}
	329
	330	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_BYPASS;
	331	result = tc_classify(skb, q->filter_list, &res);
	332	if (result >= 0) {
	333	#ifdef CONFIG_NET_CLS_ACT
	334	switch (result) {
	335	case TC_ACT_QUEUED:
	336	case TC_ACT_STOLEN:
	337	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_STOLEN;
	338	case TC_ACT_SHOT:
	339	return NULL;
	340	}
	341	#endif
	342	cl = (struct drr_class *)res.class;
	343	if (cl == NULL)
	344	cl = drr_find_class(sch, res.classid);
	345	return cl;
	346	}
	347	return NULL;
	348	}
349
350	static int drr_enqueue(struct sk_buff skb, struct Qdisc sch)
351	{
352	struct drr_sched *q = qdisc_priv(sch);
353	struct drr_class *cl;
13d2a1d2 PM	354	int err;
	355
	356	cl = drr_classify(skb, sch, &err);
	357	if (cl == NULL) {
	358	if (err & __NET_XMIT_BYPASS)
	359	sch->qstats.drops++;
	360	kfree_skb(skb);
	361	return err;
	362	}
	363
13d2a1d2 PM	364	err = qdisc_enqueue(skb, cl->qdisc);
	365	if (unlikely(err != NET_XMIT_SUCCESS)) {
	366	if (net_xmit_drop_count(err)) {
	367	cl->qstats.drops++;
	368	sch->qstats.drops++;
	369	}
	370	return err;
	371	}
	372
	373	if (cl->qdisc->q.qlen == 1) {
	374	list_add_tail(&cl->alist, &q->active);
	375	cl->deficit = cl->quantum;
	376	}
	377
bfe0d029	378	bstats_update(&cl->bstats, skb);
13d2a1d2 PM	379
	380	sch->q.qlen++;
	381	return err;
	382	}
	383
	384	static struct sk_buff drr_dequeue(struct Qdisc sch)
	385	{
	386	struct drr_sched *q = qdisc_priv(sch);
	387	struct drr_class *cl;
	388	struct sk_buff *skb;
	389	unsigned int len;
	390
3f0947c3 PM	391	if (list_empty(&q->active))
	392	goto out;
	393	while (1) {
13d2a1d2 PM	394	cl = list_first_entry(&q->active, struct drr_class, alist);
	395	skb = cl->qdisc->ops->peek(cl->qdisc);
	396	if (skb == NULL)
3f0947c3	397	goto out;
13d2a1d2 PM	398
	399	len = qdisc_pkt_len(skb);
	400	if (len <= cl->deficit) {
	401	cl->deficit -= len;
	402	skb = qdisc_dequeue_peeked(cl->qdisc);
	403	if (cl->qdisc->q.qlen == 0)
	404	list_del(&cl->alist);
9190b3b3	405	qdisc_bstats_update(sch, skb);
13d2a1d2 PM	406	sch->q.qlen--;
	407	return skb;
	408	}
	409
	410	cl->deficit += cl->quantum;
13d2a1d2 PM	411	list_move_tail(&cl->alist, &q->active);
13d2a1d2 PM	412	}
3f0947c3	413	out:
13d2a1d2 PM	414	return NULL;
	415	}
	416
	417	static unsigned int drr_drop(struct Qdisc *sch)
	418	{
	419	struct drr_sched *q = qdisc_priv(sch);
	420	struct drr_class *cl;
	421	unsigned int len;
	422
	423	list_for_each_entry(cl, &q->active, alist) {
	424	if (cl->qdisc->ops->drop) {
	425	len = cl->qdisc->ops->drop(cl->qdisc);
	426	if (len > 0) {
98aa9c80	427	sch->q.qlen--;
13d2a1d2 PM	428	if (cl->qdisc->q.qlen == 0)
	429	list_del(&cl->alist);
	430	return len;
	431	}
	432	}
	433	}
	434	return 0;
	435	}
	436
	437	static int drr_init_qdisc(struct Qdisc sch, struct nlattr opt)
	438	{
	439	struct drr_sched *q = qdisc_priv(sch);
	440	int err;
	441
	442	err = qdisc_class_hash_init(&q->clhash);
	443	if (err < 0)
	444	return err;
	445	INIT_LIST_HEAD(&q->active);
	446	return 0;
	447	}
	448
	449	static void drr_reset_qdisc(struct Qdisc *sch)
	450	{
	451	struct drr_sched *q = qdisc_priv(sch);
	452	struct drr_class *cl;
	453	struct hlist_node *n;
	454	unsigned int i;
	455
	456	for (i = 0; i < q->clhash.hashsize; i++) {
	457	hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
	458	if (cl->qdisc->q.qlen)
	459	list_del(&cl->alist);
	460	qdisc_reset(cl->qdisc);
	461	}
	462	}
	463	sch->q.qlen = 0;
	464	}
	465
	466	static void drr_destroy_qdisc(struct Qdisc *sch)
	467	{
	468	struct drr_sched *q = qdisc_priv(sch);
	469	struct drr_class *cl;
	470	struct hlist_node n, next;
	471	unsigned int i;
	472
	473	tcf_destroy_chain(&q->filter_list);
	474
	475	for (i = 0; i < q->clhash.hashsize; i++) {
	476	hlist_for_each_entry_safe(cl, n, next, &q->clhash.hash[i],
	477	common.hnode)
	478	drr_destroy_class(sch, cl);
	479	}
	480	qdisc_class_hash_destroy(&q->clhash);
	481	}
	482
	483	static const struct Qdisc_class_ops drr_class_ops = {
	484	.change = drr_change_class,
	485	.delete = drr_delete_class,
	486	.get = drr_get_class,
	487	.put = drr_put_class,
	488	.tcf_chain = drr_tcf_chain,
	489	.bind_tcf = drr_bind_tcf,
	490	.unbind_tcf = drr_unbind_tcf,
	491	.graft = drr_graft_class,
492	.leaf = drr_class_leaf,
493	.qlen_notify = drr_qlen_notify,
494	.dump = drr_dump_class,
495	.dump_stats = drr_dump_class_stats,
496	.walk = drr_walk,
497	};
498
499	static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
500	.cl_ops = &drr_class_ops,
501	.id = "drr",
502	.priv_size = sizeof(struct drr_sched),
503	.enqueue = drr_enqueue,
504	.dequeue = drr_dequeue,
505	.peek = qdisc_peek_dequeued,
506	.drop = drr_drop,
507	.init = drr_init_qdisc,
508	.reset = drr_reset_qdisc,
509	.destroy = drr_destroy_qdisc,
510	.owner = THIS_MODULE,
511	};
512
513	static int __init drr_init(void)
514	{
515	return register_qdisc(&drr_qdisc_ops);
516	}
517
518	static void __exit drr_exit(void)
519	{
520	unregister_qdisc(&drr_qdisc_ops);
521	}
522
523	module_init(drr_init);
524	module_exit(drr_exit);
525	MODULE_LICENSE("GPL");