[mirror_ubuntu-jammy-kernel.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_packed		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,
						    qdisc_root_sleeping_running(sch),
						    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;

	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,
					    qdisc_root_sleeping_running(sch),
					    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(qdisc_root_sleeping_running(sch),
				  d, NULL, &cl->bstats) < 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 (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;
	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);
		}
	}
	sch->qstats.backlog = 0;
	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 *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
c1a8f1f1	22	struct gnet_stats_basic_packed 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,
edb09eb1 ED	88	NULL,
edb09eb1 ED	89	qdisc_root_sleeping_running(sch),
71bcb09a	90	tca[TCA_RATE]);
a7c31693 AA	91	if (err) {
a7c31693 AA	92	NL_SET_ERR_MSG(extack, "Failed to replace estimator");
71bcb09a	93	return err;
a7c31693	94	}
71bcb09a SH	95	}
71bcb09a SH	96
13d2a1d2 PM	97	sch_tree_lock(sch);
	98	if (tb[TCA_DRR_QUANTUM])
	99	cl->quantum = quantum;
	100	sch_tree_unlock(sch);
	101
13d2a1d2 PM	102	return 0;
	103	}
	104
	105	cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
	106	if (cl == NULL)
	107	return -ENOBUFS;
	108
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,
edb09eb1 ED	121	NULL,
edb09eb1 ED	122	qdisc_root_sleeping_running(sch),
71bcb09a SH	123	tca[TCA_RATE]);
71bcb09a SH	124	if (err) {
a7c31693	125	NL_SET_ERR_MSG(extack, "Failed to replace estimator");
86bd446b	126	qdisc_put(cl->qdisc);
71bcb09a SH	127	kfree(cl);
	128	return err;
	129	}
	130	}
13d2a1d2 PM	131
	132	sch_tree_lock(sch);
	133	qdisc_class_hash_insert(&q->clhash, &cl->common);
	134	sch_tree_unlock(sch);
	135
	136	qdisc_class_hash_grow(sch, &q->clhash);
	137
	138	*arg = (unsigned long)cl;
	139	return 0;
	140	}
	141
	142	static void drr_destroy_class(struct Qdisc sch, struct drr_class cl)
	143	{
1c0d32fd	144	gen_kill_estimator(&cl->rate_est);
86bd446b	145	qdisc_put(cl->qdisc);
13d2a1d2 PM	146	kfree(cl);
	147	}
	148
4dd78a73 MM	149	static int drr_delete_class(struct Qdisc *sch, unsigned long arg,
4dd78a73 MM	150	struct netlink_ext_ack *extack)
13d2a1d2 PM	151	{
	152	struct drr_sched *q = qdisc_priv(sch);
	153	struct drr_class cl = (struct drr_class )arg;
	154
	155	if (cl->filter_cnt > 0)
	156	return -EBUSY;
	157
	158	sch_tree_lock(sch);
	159
e5f0e8f8	160	qdisc_purge_queue(cl->qdisc);
13d2a1d2 PM	161	qdisc_class_hash_remove(&q->clhash, &cl->common);
13d2a1d2 PM	162
13d2a1d2	163	sch_tree_unlock(sch);
13d2a1d2	164
143976ce WC	165	drr_destroy_class(sch, cl);
143976ce WC	166	return 0;
13d2a1d2 PM	167	}
13d2a1d2 PM	168
143976ce	169	static unsigned long drr_search_class(struct Qdisc *sch, u32 classid)
13d2a1d2	170	{
143976ce	171	return (unsigned long)drr_find_class(sch, classid);
13d2a1d2 PM	172	}
13d2a1d2 PM	173
cbaacc4e AA	174	static struct tcf_block drr_tcf_block(struct Qdisc sch, unsigned long cl,
cbaacc4e AA	175	struct netlink_ext_ack *extack)
13d2a1d2 PM	176	{
	177	struct drr_sched *q = qdisc_priv(sch);
	178
a7c31693 AA	179	if (cl) {
a7c31693 AA	180	NL_SET_ERR_MSG(extack, "DRR classid must be zero");
13d2a1d2	181	return NULL;
a7c31693	182	}
13d2a1d2	183
6529eaba	184	return q->block;
13d2a1d2 PM	185	}
	186
	187	static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
	188	u32 classid)
	189	{
	190	struct drr_class *cl = drr_find_class(sch, classid);
	191
	192	if (cl != NULL)
	193	cl->filter_cnt++;
	194
	195	return (unsigned long)cl;
	196	}
	197
	198	static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
	199	{
	200	struct drr_class cl = (struct drr_class )arg;
	201
	202	cl->filter_cnt--;
	203	}
	204
	205	static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
653d6fd6 AA	206	struct Qdisc new, struct Qdisc *old,
653d6fd6 AA	207	struct netlink_ext_ack *extack)
13d2a1d2 PM	208	{
	209	struct drr_class cl = (struct drr_class )arg;
	210
	211	if (new == NULL) {
a38a9882 AA	212	new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
a38a9882 AA	213	cl->common.classid, NULL);
13d2a1d2 PM	214	if (new == NULL)
	215	new = &noop_qdisc;
	216	}
	217
86a7996c	218	*old = qdisc_replace(sch, new, &cl->qdisc);
13d2a1d2 PM	219	return 0;
	220	}
	221
	222	static struct Qdisc drr_class_leaf(struct Qdisc sch, unsigned long arg)
	223	{
	224	struct drr_class cl = (struct drr_class )arg;
	225
	226	return cl->qdisc;
	227	}
	228
	229	static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
	230	{
	231	struct drr_class cl = (struct drr_class )arg;
	232
95946658	233	list_del(&cl->alist);
13d2a1d2 PM	234	}
	235
	236	static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
	237	struct sk_buff skb, struct tcmsg tcm)
	238	{
	239	struct drr_class cl = (struct drr_class )arg;
	240	struct nlattr *nest;
	241
	242	tcm->tcm_parent = TC_H_ROOT;
	243	tcm->tcm_handle = cl->common.classid;
	244	tcm->tcm_info = cl->qdisc->handle;
	245
ae0be8de	246	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
13d2a1d2 PM	247	if (nest == NULL)
13d2a1d2 PM	248	goto nla_put_failure;
1b34ec43 DM	249	if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
1b34ec43 DM	250	goto nla_put_failure;
13d2a1d2 PM	251	return nla_nest_end(skb, nest);
	252
	253	nla_put_failure:
	254	nla_nest_cancel(skb, nest);
	255	return -EMSGSIZE;
	256	}
	257
	258	static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
	259	struct gnet_dump *d)
	260	{
	261	struct drr_class cl = (struct drr_class )arg;
5dd431b6 PA	262	__u32 qlen = qdisc_qlen_sum(cl->qdisc);
5dd431b6 PA	263	struct Qdisc *cl_q = cl->qdisc;
13d2a1d2 PM	264	struct tc_drr_stats xstats;
	265
	266	memset(&xstats, 0, sizeof(xstats));
64015853	267	if (qlen)
13d2a1d2 PM	268	xstats.deficit = cl->deficit;
13d2a1d2 PM	269
edb09eb1 ED	270	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
edb09eb1 ED	271	d, NULL, &cl->bstats) < 0 \|\|
1c0d32fd	272	gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 \|\|
5dd431b6	273	gnet_stats_copy_queue(d, cl_q->cpu_qstats, &cl_q->qstats, qlen) < 0)
13d2a1d2 PM	274	return -1;
	275
	276	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
	277	}
	278
	279	static void drr_walk(struct Qdisc sch, struct qdisc_walker arg)
	280	{
	281	struct drr_sched *q = qdisc_priv(sch);
	282	struct drr_class *cl;
13d2a1d2 PM	283	unsigned int i;
	284
	285	if (arg->stop)
	286	return;
	287
	288	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	289	hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
13d2a1d2 PM	290	if (arg->count < arg->skip) {
	291	arg->count++;
	292	continue;
	293	}
	294	if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
	295	arg->stop = 1;
	296	return;
	297	}
	298	arg->count++;
	299	}
	300	}
	301	}
	302
	303	static struct drr_class drr_classify(struct sk_buff skb, struct Qdisc *sch,
	304	int *qerr)
	305	{
	306	struct drr_sched *q = qdisc_priv(sch);
	307	struct drr_class *cl;
	308	struct tcf_result res;
25d8c0d5	309	struct tcf_proto *fl;
13d2a1d2 PM	310	int result;
	311
	312	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
	313	cl = drr_find_class(sch, skb->priority);
	314	if (cl != NULL)
	315	return cl;
	316	}
	317
	318	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_BYPASS;
25d8c0d5	319	fl = rcu_dereference_bh(q->filter_list);
3aa26055	320	result = tcf_classify(skb, NULL, fl, &res, false);
13d2a1d2 PM	321	if (result >= 0) {
	322	#ifdef CONFIG_NET_CLS_ACT
	323	switch (result) {
	324	case TC_ACT_QUEUED:
	325	case TC_ACT_STOLEN:
e25ea21f	326	case TC_ACT_TRAP:
13d2a1d2	327	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_STOLEN;
964201de	328	fallthrough;
13d2a1d2 PM	329	case TC_ACT_SHOT:
	330	return NULL;
	331	}
	332	#endif
	333	cl = (struct drr_class *)res.class;
	334	if (cl == NULL)
	335	cl = drr_find_class(sch, res.classid);
	336	return cl;
	337	}
	338	return NULL;
	339	}
	340
ac5c66f2	341	static int drr_enqueue(struct sk_buff skb, struct Qdisc sch,
520ac30f	342	struct sk_buff **to_free)
13d2a1d2	343	{
f6bab199	344	unsigned int len = qdisc_pkt_len(skb);
13d2a1d2 PM	345	struct drr_sched *q = qdisc_priv(sch);
13d2a1d2 PM	346	struct drr_class *cl;
f54ba779	347	int err = 0;
37d9cf1a	348	bool first;
13d2a1d2 PM	349
	350	cl = drr_classify(skb, sch, &err);
	351	if (cl == NULL) {
	352	if (err & __NET_XMIT_BYPASS)
25331d6c	353	qdisc_qstats_drop(sch);
520ac30f	354	__qdisc_drop(skb, to_free);
13d2a1d2 PM	355	return err;
	356	}
	357
37d9cf1a	358	first = !cl->qdisc->q.qlen;
ac5c66f2	359	err = qdisc_enqueue(skb, cl->qdisc, to_free);
13d2a1d2 PM	360	if (unlikely(err != NET_XMIT_SUCCESS)) {
	361	if (net_xmit_drop_count(err)) {
	362	cl->qstats.drops++;
25331d6c	363	qdisc_qstats_drop(sch);
13d2a1d2 PM	364	}
	365	return err;
	366	}
	367
37d9cf1a	368	if (first) {
13d2a1d2 PM	369	list_add_tail(&cl->alist, &q->active);
	370	cl->deficit = cl->quantum;
	371	}
	372
f6bab199	373	sch->qstats.backlog += len;
13d2a1d2 PM	374	sch->q.qlen++;
	375	return err;
	376	}
	377
	378	static struct sk_buff drr_dequeue(struct Qdisc sch)
	379	{
	380	struct drr_sched *q = qdisc_priv(sch);
	381	struct drr_class *cl;
	382	struct sk_buff *skb;
	383	unsigned int len;
	384
3f0947c3 PM	385	if (list_empty(&q->active))
	386	goto out;
	387	while (1) {
13d2a1d2 PM	388	cl = list_first_entry(&q->active, struct drr_class, alist);
13d2a1d2 PM	389	skb = cl->qdisc->ops->peek(cl->qdisc);
6e765a00 FW	390	if (skb == NULL) {
6e765a00 FW	391	qdisc_warn_nonwc(__func__, cl->qdisc);
3f0947c3	392	goto out;
6e765a00	393	}
13d2a1d2 PM	394
	395	len = qdisc_pkt_len(skb);
	396	if (len <= cl->deficit) {
	397	cl->deficit -= len;
	398	skb = qdisc_dequeue_peeked(cl->qdisc);
df3eb6cd BH	399	if (unlikely(skb == NULL))
df3eb6cd BH	400	goto out;
13d2a1d2 PM	401	if (cl->qdisc->q.qlen == 0)
13d2a1d2 PM	402	list_del(&cl->alist);
2dd875ff ED	403
2dd875ff ED	404	bstats_update(&cl->bstats, skb);
9190b3b3	405	qdisc_bstats_update(sch, skb);
6a73b571	406	qdisc_qstats_backlog_dec(sch, skb);
13d2a1d2 PM	407	sch->q.qlen--;
	408	return skb;
	409	}
	410
	411	cl->deficit += cl->quantum;
13d2a1d2 PM	412	list_move_tail(&cl->alist, &q->active);
13d2a1d2 PM	413	}
3f0947c3	414	out:
13d2a1d2 PM	415	return NULL;
	416	}
	417
e63d7dfd AA	418	static int drr_init_qdisc(struct Qdisc sch, struct nlattr opt,
e63d7dfd AA	419	struct netlink_ext_ack *extack)
13d2a1d2 PM	420	{
	421	struct drr_sched *q = qdisc_priv(sch);
	422	int err;
	423
8d1a77f9	424	err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
6529eaba JP	425	if (err)
6529eaba JP	426	return err;
13d2a1d2 PM	427	err = qdisc_class_hash_init(&q->clhash);
	428	if (err < 0)
	429	return err;
	430	INIT_LIST_HEAD(&q->active);
	431	return 0;
	432	}
	433
	434	static void drr_reset_qdisc(struct Qdisc *sch)
	435	{
	436	struct drr_sched *q = qdisc_priv(sch);
	437	struct drr_class *cl;
13d2a1d2 PM	438	unsigned int i;
	439
	440	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	441	hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
13d2a1d2 PM	442	if (cl->qdisc->q.qlen)
	443	list_del(&cl->alist);
	444	qdisc_reset(cl->qdisc);
	445	}
	446	}
6a73b571	447	sch->qstats.backlog = 0;
13d2a1d2 PM	448	sch->q.qlen = 0;
	449	}
	450
	451	static void drr_destroy_qdisc(struct Qdisc *sch)
	452	{
	453	struct drr_sched *q = qdisc_priv(sch);
	454	struct drr_class *cl;
b67bfe0d	455	struct hlist_node *next;
13d2a1d2 PM	456	unsigned int i;
13d2a1d2 PM	457
6529eaba	458	tcf_block_put(q->block);
13d2a1d2 PM	459
13d2a1d2 PM	460	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	461	hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
13d2a1d2 PM	462	common.hnode)
	463	drr_destroy_class(sch, cl);
	464	}
	465	qdisc_class_hash_destroy(&q->clhash);
	466	}
	467
	468	static const struct Qdisc_class_ops drr_class_ops = {
	469	.change = drr_change_class,
	470	.delete = drr_delete_class,
143976ce	471	.find = drr_search_class,
6529eaba	472	.tcf_block = drr_tcf_block,
13d2a1d2 PM	473	.bind_tcf = drr_bind_tcf,
	474	.unbind_tcf = drr_unbind_tcf,
	475	.graft = drr_graft_class,
	476	.leaf = drr_class_leaf,
	477	.qlen_notify = drr_qlen_notify,
	478	.dump = drr_dump_class,
	479	.dump_stats = drr_dump_class_stats,
	480	.walk = drr_walk,
	481	};
	482
	483	static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
	484	.cl_ops = &drr_class_ops,
	485	.id = "drr",
	486	.priv_size = sizeof(struct drr_sched),
	487	.enqueue = drr_enqueue,
	488	.dequeue = drr_dequeue,
	489	.peek = qdisc_peek_dequeued,
13d2a1d2 PM	490	.init = drr_init_qdisc,
	491	.reset = drr_reset_qdisc,
	492	.destroy = drr_destroy_qdisc,
	493	.owner = THIS_MODULE,
	494	};
	495
	496	static int __init drr_init(void)
	497	{
	498	return register_qdisc(&drr_qdisc_ops);
	499	}
	500
	501	static void __exit drr_exit(void)
	502	{
	503	unregister_qdisc(&drr_qdisc_ops);
	504	}
	505
	506	module_init(drr_init);
	507	module_exit(drr_exit);
	508	MODULE_LICENSE("GPL");