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

// SPDX-License-Identifier: GPL-2.0-only
/*
 * net/sched/sch_drr.c         Deficit Round Robin scheduler
 *
 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
 */

#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			filter_cnt;

	struct gnet_stats_basic_sync		bstats;
	struct gnet_stats_queue		qstats;
	struct net_rate_estimator __rcu *rate_est;
	struct list_head		alist;
	struct Qdisc			*qdisc;

	u32				quantum;
	u32				deficit;
};

struct drr_sched {
	struct list_head		active;
	struct tcf_proto __rcu		*filter_list;
	struct tcf_block		*block;
	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 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 netlink_ext_ack *extack)
{
	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) {
		NL_SET_ERR_MSG(extack, "DRR options are required for this operation");
		return -EINVAL;
	}

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

	if (tb[TCA_DRR_QUANTUM]) {
		quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
		if (quantum == 0) {
			NL_SET_ERR_MSG(extack, "Specified DRR quantum cannot be zero");
			return -EINVAL;
		}
	} else
		quantum = psched_mtu(qdisc_dev(sch));

	if (cl != NULL) {
		if (tca[TCA_RATE]) {
			err = gen_replace_estimator(&cl->bstats, NULL,
						    &cl->rate_est,
						    NULL, true,
						    tca[TCA_RATE]);
			if (err) {
				NL_SET_ERR_MSG(extack, "Failed to replace estimator");
				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;

	gnet_stats_basic_sync_init(&cl->bstats);
	cl->common.classid = classid;
	cl->quantum	   = quantum;
	cl->qdisc	   = qdisc_create_dflt(sch->dev_queue,
					       &pfifo_qdisc_ops, classid,
					       NULL);
	if (cl->qdisc == NULL)
		cl->qdisc = &noop_qdisc;
	else
		qdisc_hash_add(cl->qdisc, true);

	if (tca[TCA_RATE]) {
		err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est,
					    NULL, true, tca[TCA_RATE]);
		if (err) {
			NL_SET_ERR_MSG(extack, "Failed to replace estimator");
			qdisc_put(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->rate_est);
	qdisc_put(cl->qdisc);
	kfree(cl);
}

static int drr_delete_class(struct Qdisc *sch, unsigned long arg,
			    struct netlink_ext_ack *extack)
{
	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);

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

	sch_tree_unlock(sch);

	drr_destroy_class(sch, cl);
	return 0;
}

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

static struct tcf_block *drr_tcf_block(struct Qdisc *sch, unsigned long cl,
				       struct netlink_ext_ack *extack)
{
	struct drr_sched *q = qdisc_priv(sch);

	if (cl) {
		NL_SET_ERR_MSG(extack, "DRR classid must be zero");
		return NULL;
	}

	return q->block;
}

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 netlink_ext_ack *extack)
{
	struct drr_class *cl = (struct drr_class *)arg;

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

	*old = qdisc_replace(sch, new, &cl->qdisc);
	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;

	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_noflag(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;
	if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
		goto nla_put_failure;
	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;
	__u32 qlen = qdisc_qlen_sum(cl->qdisc);
	struct Qdisc *cl_q = cl->qdisc;
	struct tc_drr_stats xstats;

	memset(&xstats, 0, sizeof(xstats));
	if (qlen)
		xstats.deficit = cl->deficit;

	if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 ||
	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
	    gnet_stats_copy_queue(d, cl_q->cpu_qstats, &cl_q->qstats, qlen) < 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;
	unsigned int i;

	if (arg->stop)
		return;

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
			if (!tc_qdisc_stats_dump(sch, (unsigned long)cl, arg))
				return;
		}
	}
}

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;
	struct tcf_proto *fl;
	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;
	fl = rcu_dereference_bh(q->filter_list);
	result = tcf_classify(skb, NULL, fl, &res, false);
	if (result >= 0) {
#ifdef CONFIG_NET_CLS_ACT
		switch (result) {
		case TC_ACT_QUEUED:
		case TC_ACT_STOLEN:
		case TC_ACT_TRAP:
			*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
			fallthrough;
		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 sk_buff **to_free)
{
	unsigned int len = qdisc_pkt_len(skb);
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	int err = 0;
	bool first;

	cl = drr_classify(skb, sch, &err);
	if (cl == NULL) {
		if (err & __NET_XMIT_BYPASS)
			qdisc_qstats_drop(sch);
		__qdisc_drop(skb, to_free);
		return err;
	}

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

	if (first) {
		list_add_tail(&cl->alist, &q->active);
		cl->deficit = cl->quantum;
	}

	sch->qstats.backlog += len;
	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) {
			qdisc_warn_nonwc(__func__, cl->qdisc);
			goto out;
		}

		len = qdisc_pkt_len(skb);
		if (len <= cl->deficit) {
			cl->deficit -= len;
			skb = qdisc_dequeue_peeked(cl->qdisc);
			if (unlikely(skb == NULL))
				goto out;
			if (cl->qdisc->q.qlen == 0)
				list_del(&cl->alist);

			bstats_update(&cl->bstats, skb);
			qdisc_bstats_update(sch, skb);
			qdisc_qstats_backlog_dec(sch, skb);
			sch->q.qlen--;
			return skb;
		}

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

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

	err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
	if (err)
		return 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;
	unsigned int i;

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

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

	tcf_block_put(q->block);

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry_safe(cl, 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,
	.find		= drr_search_class,
	.tcf_block	= drr_tcf_block,
	.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,
	.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
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
13d2a1d2 PM	2	/*
	3	* net/sched/sch_drr.c Deficit Round Robin scheduler
	4	*
	5	* Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
13d2a1d2 PM	6	*/
	7
	8	#include <linux/module.h>
5a0e3ad6	9	#include <linux/slab.h>
13d2a1d2 PM	10	#include <linux/init.h>
	11	#include <linux/errno.h>
	12	#include <linux/netdevice.h>
	13	#include <linux/pkt_sched.h>
	14	#include <net/sch_generic.h>
	15	#include <net/pkt_sched.h>
	16	#include <net/pkt_cls.h>
	17
	18	struct drr_class {
	19	struct Qdisc_class_common common;
13d2a1d2 PM	20	unsigned int filter_cnt;
13d2a1d2 PM	21
50dc9a85	22	struct gnet_stats_basic_sync bstats;
13d2a1d2	23	struct gnet_stats_queue qstats;
1c0d32fd	24	struct net_rate_estimator __rcu *rate_est;
13d2a1d2 PM	25	struct list_head alist;
	26	struct Qdisc *qdisc;
	27
	28	u32 quantum;
	29	u32 deficit;
	30	};
	31
	32	struct drr_sched {
	33	struct list_head active;
25d8c0d5	34	struct tcf_proto __rcu *filter_list;
6529eaba	35	struct tcf_block *block;
13d2a1d2 PM	36	struct Qdisc_class_hash clhash;
	37	};
	38
	39	static struct drr_class drr_find_class(struct Qdisc sch, u32 classid)
	40	{
	41	struct drr_sched *q = qdisc_priv(sch);
	42	struct Qdisc_class_common *clc;
	43
	44	clc = qdisc_class_find(&q->clhash, classid);
	45	if (clc == NULL)
	46	return NULL;
	47	return container_of(clc, struct drr_class, common);
	48	}
	49
13d2a1d2 PM	50	static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
	51	[TCA_DRR_QUANTUM] = { .type = NLA_U32 },
	52	};
	53
	54	static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
793d81d6 AA	55	struct nlattr *tca, unsigned long arg,
793d81d6 AA	56	struct netlink_ext_ack *extack)
13d2a1d2 PM	57	{
	58	struct drr_sched *q = qdisc_priv(sch);
	59	struct drr_class cl = (struct drr_class )*arg;
1844f747	60	struct nlattr *opt = tca[TCA_OPTIONS];
13d2a1d2 PM	61	struct nlattr *tb[TCA_DRR_MAX + 1];
	62	u32 quantum;
	63	int err;
	64
a7c31693 AA	65	if (!opt) {
a7c31693 AA	66	NL_SET_ERR_MSG(extack, "DRR options are required for this operation");
1844f747	67	return -EINVAL;
a7c31693	68	}
1844f747	69
8cb08174 JB	70	err = nla_parse_nested_deprecated(tb, TCA_DRR_MAX, opt, drr_policy,
8cb08174 JB	71	extack);
13d2a1d2 PM	72	if (err < 0)
	73	return err;
	74
	75	if (tb[TCA_DRR_QUANTUM]) {
	76	quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
a7c31693 AA	77	if (quantum == 0) {
a7c31693 AA	78	NL_SET_ERR_MSG(extack, "Specified DRR quantum cannot be zero");
13d2a1d2	79	return -EINVAL;
a7c31693	80	}
13d2a1d2 PM	81	} else
	82	quantum = psched_mtu(qdisc_dev(sch));
	83
	84	if (cl != NULL) {
71bcb09a	85	if (tca[TCA_RATE]) {
22e0f8b9 JF	86	err = gen_replace_estimator(&cl->bstats, NULL,
22e0f8b9 JF	87	&cl->rate_est,
29cbcd85	88	NULL, true,
71bcb09a	89	tca[TCA_RATE]);
a7c31693 AA	90	if (err) {
a7c31693 AA	91	NL_SET_ERR_MSG(extack, "Failed to replace estimator");
71bcb09a	92	return err;
a7c31693	93	}
71bcb09a SH	94	}
71bcb09a SH	95
13d2a1d2 PM	96	sch_tree_lock(sch);
	97	if (tb[TCA_DRR_QUANTUM])
	98	cl->quantum = quantum;
	99	sch_tree_unlock(sch);
	100
13d2a1d2 PM	101	return 0;
	102	}
	103
	104	cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
	105	if (cl == NULL)
	106	return -ENOBUFS;
	107
50dc9a85	108	gnet_stats_basic_sync_init(&cl->bstats);
13d2a1d2 PM	109	cl->common.classid = classid;
13d2a1d2 PM	110	cl->quantum = quantum;
3511c913	111	cl->qdisc = qdisc_create_dflt(sch->dev_queue,
a38a9882 AA	112	&pfifo_qdisc_ops, classid,
a38a9882 AA	113	NULL);
13d2a1d2 PM	114	if (cl->qdisc == NULL)
13d2a1d2 PM	115	cl->qdisc = &noop_qdisc;
49b49971 JK	116	else
49b49971 JK	117	qdisc_hash_add(cl->qdisc, true);
13d2a1d2	118
71bcb09a	119	if (tca[TCA_RATE]) {
22e0f8b9	120	err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est,
29cbcd85	121	NULL, true, tca[TCA_RATE]);
71bcb09a	122	if (err) {
a7c31693	123	NL_SET_ERR_MSG(extack, "Failed to replace estimator");
86bd446b	124	qdisc_put(cl->qdisc);
71bcb09a SH	125	kfree(cl);
	126	return err;
	127	}
	128	}
13d2a1d2 PM	129
	130	sch_tree_lock(sch);
	131	qdisc_class_hash_insert(&q->clhash, &cl->common);
	132	sch_tree_unlock(sch);
	133
	134	qdisc_class_hash_grow(sch, &q->clhash);
	135
	136	*arg = (unsigned long)cl;
	137	return 0;
	138	}
	139
	140	static void drr_destroy_class(struct Qdisc sch, struct drr_class cl)
	141	{
1c0d32fd	142	gen_kill_estimator(&cl->rate_est);
86bd446b	143	qdisc_put(cl->qdisc);
13d2a1d2 PM	144	kfree(cl);
	145	}
	146
4dd78a73 MM	147	static int drr_delete_class(struct Qdisc *sch, unsigned long arg,
4dd78a73 MM	148	struct netlink_ext_ack *extack)
13d2a1d2 PM	149	{
	150	struct drr_sched *q = qdisc_priv(sch);
	151	struct drr_class cl = (struct drr_class )arg;
	152
	153	if (cl->filter_cnt > 0)
	154	return -EBUSY;
	155
	156	sch_tree_lock(sch);
	157
e5f0e8f8	158	qdisc_purge_queue(cl->qdisc);
13d2a1d2 PM	159	qdisc_class_hash_remove(&q->clhash, &cl->common);
13d2a1d2 PM	160
13d2a1d2	161	sch_tree_unlock(sch);
13d2a1d2	162
143976ce WC	163	drr_destroy_class(sch, cl);
143976ce WC	164	return 0;
13d2a1d2 PM	165	}
13d2a1d2 PM	166
143976ce	167	static unsigned long drr_search_class(struct Qdisc *sch, u32 classid)
13d2a1d2	168	{
143976ce	169	return (unsigned long)drr_find_class(sch, classid);
13d2a1d2 PM	170	}
13d2a1d2 PM	171
cbaacc4e AA	172	static struct tcf_block drr_tcf_block(struct Qdisc sch, unsigned long cl,
cbaacc4e AA	173	struct netlink_ext_ack *extack)
13d2a1d2 PM	174	{
	175	struct drr_sched *q = qdisc_priv(sch);
	176
a7c31693 AA	177	if (cl) {
a7c31693 AA	178	NL_SET_ERR_MSG(extack, "DRR classid must be zero");
13d2a1d2	179	return NULL;
a7c31693	180	}
13d2a1d2	181
6529eaba	182	return q->block;
13d2a1d2 PM	183	}
	184
	185	static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
	186	u32 classid)
	187	{
	188	struct drr_class *cl = drr_find_class(sch, classid);
	189
	190	if (cl != NULL)
	191	cl->filter_cnt++;
	192
	193	return (unsigned long)cl;
	194	}
	195
	196	static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
	197	{
	198	struct drr_class cl = (struct drr_class )arg;
	199
	200	cl->filter_cnt--;
	201	}
	202
	203	static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
653d6fd6 AA	204	struct Qdisc new, struct Qdisc *old,
653d6fd6 AA	205	struct netlink_ext_ack *extack)
13d2a1d2 PM	206	{
	207	struct drr_class cl = (struct drr_class )arg;
	208
	209	if (new == NULL) {
a38a9882 AA	210	new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
a38a9882 AA	211	cl->common.classid, NULL);
13d2a1d2 PM	212	if (new == NULL)
	213	new = &noop_qdisc;
	214	}
	215
86a7996c	216	*old = qdisc_replace(sch, new, &cl->qdisc);
13d2a1d2 PM	217	return 0;
	218	}
	219
	220	static struct Qdisc drr_class_leaf(struct Qdisc sch, unsigned long arg)
	221	{
	222	struct drr_class cl = (struct drr_class )arg;
	223
	224	return cl->qdisc;
	225	}
	226
	227	static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
	228	{
	229	struct drr_class cl = (struct drr_class )arg;
	230
95946658	231	list_del(&cl->alist);
13d2a1d2 PM	232	}
	233
	234	static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
	235	struct sk_buff skb, struct tcmsg tcm)
	236	{
	237	struct drr_class cl = (struct drr_class )arg;
	238	struct nlattr *nest;
	239
	240	tcm->tcm_parent = TC_H_ROOT;
	241	tcm->tcm_handle = cl->common.classid;
	242	tcm->tcm_info = cl->qdisc->handle;
	243
ae0be8de	244	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
13d2a1d2 PM	245	if (nest == NULL)
13d2a1d2 PM	246	goto nla_put_failure;
1b34ec43 DM	247	if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
1b34ec43 DM	248	goto nla_put_failure;
13d2a1d2 PM	249	return nla_nest_end(skb, nest);
	250
	251	nla_put_failure:
	252	nla_nest_cancel(skb, nest);
	253	return -EMSGSIZE;
	254	}
	255
	256	static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
	257	struct gnet_dump *d)
	258	{
	259	struct drr_class cl = (struct drr_class )arg;
5dd431b6 PA	260	__u32 qlen = qdisc_qlen_sum(cl->qdisc);
5dd431b6 PA	261	struct Qdisc *cl_q = cl->qdisc;
13d2a1d2 PM	262	struct tc_drr_stats xstats;
	263
	264	memset(&xstats, 0, sizeof(xstats));
64015853	265	if (qlen)
13d2a1d2 PM	266	xstats.deficit = cl->deficit;
13d2a1d2 PM	267
29cbcd85	268	if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 \|\|
1c0d32fd	269	gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 \|\|
5dd431b6	270	gnet_stats_copy_queue(d, cl_q->cpu_qstats, &cl_q->qstats, qlen) < 0)
13d2a1d2 PM	271	return -1;
	272
	273	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
	274	}
	275
	276	static void drr_walk(struct Qdisc sch, struct qdisc_walker arg)
	277	{
	278	struct drr_sched *q = qdisc_priv(sch);
	279	struct drr_class *cl;
13d2a1d2 PM	280	unsigned int i;
	281
	282	if (arg->stop)
	283	return;
	284
	285	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	286	hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
e046fa89	287	if (!tc_qdisc_stats_dump(sch, (unsigned long)cl, arg))
13d2a1d2	288	return;
13d2a1d2 PM	289	}
	290	}
	291	}
	292
	293	static struct drr_class drr_classify(struct sk_buff skb, struct Qdisc *sch,
	294	int *qerr)
	295	{
	296	struct drr_sched *q = qdisc_priv(sch);
	297	struct drr_class *cl;
	298	struct tcf_result res;
25d8c0d5	299	struct tcf_proto *fl;
13d2a1d2 PM	300	int result;
	301
	302	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
	303	cl = drr_find_class(sch, skb->priority);
	304	if (cl != NULL)
	305	return cl;
	306	}
	307
	308	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_BYPASS;
25d8c0d5	309	fl = rcu_dereference_bh(q->filter_list);
3aa26055	310	result = tcf_classify(skb, NULL, fl, &res, false);
13d2a1d2 PM	311	if (result >= 0) {
	312	#ifdef CONFIG_NET_CLS_ACT
	313	switch (result) {
	314	case TC_ACT_QUEUED:
	315	case TC_ACT_STOLEN:
e25ea21f	316	case TC_ACT_TRAP:
13d2a1d2	317	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_STOLEN;
964201de	318	fallthrough;
13d2a1d2 PM	319	case TC_ACT_SHOT:
	320	return NULL;
	321	}
	322	#endif
	323	cl = (struct drr_class *)res.class;
	324	if (cl == NULL)
	325	cl = drr_find_class(sch, res.classid);
	326	return cl;
	327	}
	328	return NULL;
	329	}
	330
ac5c66f2	331	static int drr_enqueue(struct sk_buff skb, struct Qdisc sch,
520ac30f	332	struct sk_buff **to_free)
13d2a1d2	333	{
f6bab199	334	unsigned int len = qdisc_pkt_len(skb);
13d2a1d2 PM	335	struct drr_sched *q = qdisc_priv(sch);
13d2a1d2 PM	336	struct drr_class *cl;
f54ba779	337	int err = 0;
37d9cf1a	338	bool first;
13d2a1d2 PM	339
	340	cl = drr_classify(skb, sch, &err);
	341	if (cl == NULL) {
	342	if (err & __NET_XMIT_BYPASS)
25331d6c	343	qdisc_qstats_drop(sch);
520ac30f	344	__qdisc_drop(skb, to_free);
13d2a1d2 PM	345	return err;
	346	}
	347
37d9cf1a	348	first = !cl->qdisc->q.qlen;
ac5c66f2	349	err = qdisc_enqueue(skb, cl->qdisc, to_free);
13d2a1d2 PM	350	if (unlikely(err != NET_XMIT_SUCCESS)) {
	351	if (net_xmit_drop_count(err)) {
	352	cl->qstats.drops++;
25331d6c	353	qdisc_qstats_drop(sch);
13d2a1d2 PM	354	}
	355	return err;
	356	}
	357
37d9cf1a	358	if (first) {
13d2a1d2 PM	359	list_add_tail(&cl->alist, &q->active);
	360	cl->deficit = cl->quantum;
	361	}
	362
f6bab199	363	sch->qstats.backlog += len;
13d2a1d2 PM	364	sch->q.qlen++;
	365	return err;
	366	}
	367
	368	static struct sk_buff drr_dequeue(struct Qdisc sch)
	369	{
	370	struct drr_sched *q = qdisc_priv(sch);
	371	struct drr_class *cl;
	372	struct sk_buff *skb;
	373	unsigned int len;
	374
3f0947c3 PM	375	if (list_empty(&q->active))
	376	goto out;
	377	while (1) {
13d2a1d2 PM	378	cl = list_first_entry(&q->active, struct drr_class, alist);
13d2a1d2 PM	379	skb = cl->qdisc->ops->peek(cl->qdisc);
6e765a00 FW	380	if (skb == NULL) {
6e765a00 FW	381	qdisc_warn_nonwc(__func__, cl->qdisc);
3f0947c3	382	goto out;
6e765a00	383	}
13d2a1d2 PM	384
	385	len = qdisc_pkt_len(skb);
	386	if (len <= cl->deficit) {
	387	cl->deficit -= len;
	388	skb = qdisc_dequeue_peeked(cl->qdisc);
df3eb6cd BH	389	if (unlikely(skb == NULL))
df3eb6cd BH	390	goto out;
13d2a1d2 PM	391	if (cl->qdisc->q.qlen == 0)
13d2a1d2 PM	392	list_del(&cl->alist);
2dd875ff ED	393
2dd875ff ED	394	bstats_update(&cl->bstats, skb);
9190b3b3	395	qdisc_bstats_update(sch, skb);
6a73b571	396	qdisc_qstats_backlog_dec(sch, skb);
13d2a1d2 PM	397	sch->q.qlen--;
	398	return skb;
	399	}
	400
	401	cl->deficit += cl->quantum;
13d2a1d2 PM	402	list_move_tail(&cl->alist, &q->active);
13d2a1d2 PM	403	}
3f0947c3	404	out:
13d2a1d2 PM	405	return NULL;
	406	}
	407
e63d7dfd AA	408	static int drr_init_qdisc(struct Qdisc sch, struct nlattr opt,
e63d7dfd AA	409	struct netlink_ext_ack *extack)
13d2a1d2 PM	410	{
	411	struct drr_sched *q = qdisc_priv(sch);
	412	int err;
	413
8d1a77f9	414	err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
6529eaba JP	415	if (err)
6529eaba JP	416	return err;
13d2a1d2 PM	417	err = qdisc_class_hash_init(&q->clhash);
	418	if (err < 0)
	419	return err;
	420	INIT_LIST_HEAD(&q->active);
	421	return 0;
	422	}
	423
	424	static void drr_reset_qdisc(struct Qdisc *sch)
	425	{
	426	struct drr_sched *q = qdisc_priv(sch);
	427	struct drr_class *cl;
13d2a1d2 PM	428	unsigned int i;
	429
	430	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	431	hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
13d2a1d2 PM	432	if (cl->qdisc->q.qlen)
	433	list_del(&cl->alist);
	434	qdisc_reset(cl->qdisc);
	435	}
	436	}
13d2a1d2 PM	437	}
	438
	439	static void drr_destroy_qdisc(struct Qdisc *sch)
	440	{
	441	struct drr_sched *q = qdisc_priv(sch);
	442	struct drr_class *cl;
b67bfe0d	443	struct hlist_node *next;
13d2a1d2 PM	444	unsigned int i;
13d2a1d2 PM	445
6529eaba	446	tcf_block_put(q->block);
13d2a1d2 PM	447
13d2a1d2 PM	448	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	449	hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
13d2a1d2 PM	450	common.hnode)
	451	drr_destroy_class(sch, cl);
	452	}
	453	qdisc_class_hash_destroy(&q->clhash);
	454	}
	455
	456	static const struct Qdisc_class_ops drr_class_ops = {
	457	.change = drr_change_class,
	458	.delete = drr_delete_class,
143976ce	459	.find = drr_search_class,
6529eaba	460	.tcf_block = drr_tcf_block,
13d2a1d2 PM	461	.bind_tcf = drr_bind_tcf,
	462	.unbind_tcf = drr_unbind_tcf,
	463	.graft = drr_graft_class,
	464	.leaf = drr_class_leaf,
	465	.qlen_notify = drr_qlen_notify,
	466	.dump = drr_dump_class,
	467	.dump_stats = drr_dump_class_stats,
	468	.walk = drr_walk,
	469	};
	470
	471	static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
	472	.cl_ops = &drr_class_ops,
	473	.id = "drr",
	474	.priv_size = sizeof(struct drr_sched),
	475	.enqueue = drr_enqueue,
	476	.dequeue = drr_dequeue,
	477	.peek = qdisc_peek_dequeued,
13d2a1d2 PM	478	.init = drr_init_qdisc,
	479	.reset = drr_reset_qdisc,
	480	.destroy = drr_destroy_qdisc,
	481	.owner = THIS_MODULE,
	482	};
	483
	484	static int __init drr_init(void)
	485	{
	486	return register_qdisc(&drr_qdisc_ops);
	487	}
	488
	489	static void __exit drr_exit(void)
	490	{
	491	unregister_qdisc(&drr_qdisc_ops);
	492	}
	493
	494	module_init(drr_init);
	495	module_exit(drr_exit);
	496	MODULE_LICENSE("GPL");