1 files changed, 442 insertions, 0 deletions

diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
new file mode 100644
index 000000000..1c805fe05
--- /dev/null
+++ b/net/sched/sch_prio.c
@@ -0,0 +1,442 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * net/sched/sch_prio.c	Simple 3-band priority "scheduler".
+ *
+ * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ * Fixes:       19990609: J Hadi Salim <hadi@nortelnetworks.com>:
+ *              Init --  EINVAL when opt undefined
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/skbuff.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+#include <net/pkt_cls.h>
+
+struct prio_sched_data {
+	int bands;
+	struct tcf_proto __rcu *filter_list;
+	struct tcf_block *block;
+	u8  prio2band[TC_PRIO_MAX+1];
+	struct Qdisc *queues[TCQ_PRIO_BANDS];
+};
+
+
+static struct Qdisc *
+prio_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
+{
+	struct prio_sched_data *q = qdisc_priv(sch);
+	u32 band = skb->priority;
+	struct tcf_result res;
+	struct tcf_proto *fl;
+	int err;
+
+	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
+	if (TC_H_MAJ(skb->priority) != sch->handle) {
+		fl = rcu_dereference_bh(q->filter_list);
+		err = tcf_classify(skb, fl, &res, false);
+#ifdef CONFIG_NET_CLS_ACT
+		switch (err) {
+		case TC_ACT_STOLEN:
+		case TC_ACT_QUEUED:
+		case TC_ACT_TRAP:
+			*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
+			fallthrough;
+		case TC_ACT_SHOT:
+			return NULL;
+		}
+#endif
+		if (!fl || err < 0) {
+			if (TC_H_MAJ(band))
+				band = 0;
+			return q->queues[q->prio2band[band & TC_PRIO_MAX]];
+		}
+		band = res.classid;
+	}
+	band = TC_H_MIN(band) - 1;
+	if (band >= q->bands)
+		return q->queues[q->prio2band[0]];
+
+	return q->queues[band];
+}
+
+static int
+prio_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
+{
+	unsigned int len = qdisc_pkt_len(skb);
+	struct Qdisc *qdisc;
+	int ret;
+
+	qdisc = prio_classify(skb, sch, &ret);
+#ifdef CONFIG_NET_CLS_ACT
+	if (qdisc == NULL) {
+
+		if (ret & __NET_XMIT_BYPASS)
+			qdisc_qstats_drop(sch);
+		__qdisc_drop(skb, to_free);
+		return ret;
+	}
+#endif
+
+	ret = qdisc_enqueue(skb, qdisc, to_free);
+	if (ret == NET_XMIT_SUCCESS) {
+		sch->qstats.backlog += len;
+		sch->q.qlen++;
+		return NET_XMIT_SUCCESS;
+	}
+	if (net_xmit_drop_count(ret))
+		qdisc_qstats_drop(sch);
+	return ret;
+}
+
+static struct sk_buff *prio_peek(struct Qdisc *sch)
+{
+	struct prio_sched_data *q = qdisc_priv(sch);
+	int prio;
+
+	for (prio = 0; prio < q->bands; prio++) {
+		struct Qdisc *qdisc = q->queues[prio];
+		struct sk_buff *skb = qdisc->ops->peek(qdisc);
+		if (skb)
+			return skb;
+	}
+	return NULL;
+}
+
+static struct sk_buff *prio_dequeue(struct Qdisc *sch)
+{
+	struct prio_sched_data *q = qdisc_priv(sch);
+	int prio;
+
+	for (prio = 0; prio < q->bands; prio++) {
+		struct Qdisc *qdisc = q->queues[prio];
+		struct sk_buff *skb = qdisc_dequeue_peeked(qdisc);
+		if (skb) {
+			qdisc_bstats_update(sch, skb);
+			qdisc_qstats_backlog_dec(sch, skb);
+			sch->q.qlen--;
+			return skb;
+		}
+	}
+	return NULL;
+
+}
+
+static void
+prio_reset(struct Qdisc *sch)
+{
+	int prio;
+	struct prio_sched_data *q = qdisc_priv(sch);
+
+	for (prio = 0; prio < q->bands; prio++)
+		qdisc_reset(q->queues[prio]);
+}
+
+static int prio_offload(struct Qdisc *sch, struct tc_prio_qopt *qopt)
+{
+	struct net_device *dev = qdisc_dev(sch);
+	struct tc_prio_qopt_offload opt = {
+		.handle = sch->handle,
+		.parent = sch->parent,
+	};
+
+	if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
+		return -EOPNOTSUPP;
+
+	if (qopt) {
+		opt.command = TC_PRIO_REPLACE;
+		opt.replace_params.bands = qopt->bands;
+		memcpy(&opt.replace_params.priomap, qopt->priomap,
+		       TC_PRIO_MAX + 1);
+		opt.replace_params.qstats = &sch->qstats;
+	} else {
+		opt.command = TC_PRIO_DESTROY;
+	}
+
+	return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_PRIO, &opt);
+}
+
+static void
+prio_destroy(struct Qdisc *sch)
+{
+	int prio;
+	struct prio_sched_data *q = qdisc_priv(sch);
+
+	tcf_block_put(q->block);
+	prio_offload(sch, NULL);
+	for (prio = 0; prio < q->bands; prio++)
+		qdisc_put(q->queues[prio]);
+}
+
+static int prio_tune(struct Qdisc *sch, struct nlattr *opt,
+		     struct netlink_ext_ack *extack)
+{
+	struct prio_sched_data *q = qdisc_priv(sch);
+	struct Qdisc *queues[TCQ_PRIO_BANDS];
+	int oldbands = q->bands, i;
+	struct tc_prio_qopt *qopt;
+
+	if (nla_len(opt) < sizeof(*qopt))
+		return -EINVAL;
+	qopt = nla_data(opt);
+
+	if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
+		return -EINVAL;
+
+	for (i = 0; i <= TC_PRIO_MAX; i++) {
+		if (qopt->priomap[i] >= qopt->bands)
+			return -EINVAL;
+	}
+
+	/* Before commit, make sure we can allocate all new qdiscs */
+	for (i = oldbands; i < qopt->bands; i++) {
+		queues[i] = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
+					      TC_H_MAKE(sch->handle, i + 1),
+					      extack);
+		if (!queues[i]) {
+			while (i > oldbands)
+				qdisc_put(queues[--i]);
+			return -ENOMEM;
+		}
+	}
+
+	prio_offload(sch, qopt);
+	sch_tree_lock(sch);
+	q->bands = qopt->bands;
+	memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
+
+	for (i = q->bands; i < oldbands; i++)
+		qdisc_tree_flush_backlog(q->queues[i]);
+
+	for (i = oldbands; i < q->bands; i++) {
+		q->queues[i] = queues[i];
+		if (q->queues[i] != &noop_qdisc)
+			qdisc_hash_add(q->queues[i], true);
+	}
+
+	sch_tree_unlock(sch);
+
+	for (i = q->bands; i < oldbands; i++)
+		qdisc_put(q->queues[i]);
+	return 0;
+}
+
+static int prio_init(struct Qdisc *sch, struct nlattr *opt,
+		     struct netlink_ext_ack *extack)
+{
+	struct prio_sched_data *q = qdisc_priv(sch);
+	int err;
+
+	if (!opt)
+		return -EINVAL;
+
+	err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
+	if (err)
+		return err;
+
+	return prio_tune(sch, opt, extack);
+}
+
+static int prio_dump_offload(struct Qdisc *sch)
+{
+	struct tc_prio_qopt_offload hw_stats = {
+		.command = TC_PRIO_STATS,
+		.handle = sch->handle,
+		.parent = sch->parent,
+		{
+			.stats = {
+				.bstats = &sch->bstats,
+				.qstats = &sch->qstats,
+			},
+		},
+	};
+
+	return qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_PRIO, &hw_stats);
+}
+
+static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+	struct prio_sched_data *q = qdisc_priv(sch);
+	unsigned char *b = skb_tail_pointer(skb);
+	struct tc_prio_qopt opt;
+	int err;
+
+	opt.bands = q->bands;
+	memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX + 1);
+
+	err = prio_dump_offload(sch);
+	if (err)
+		goto nla_put_failure;
+
+	if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
+		goto nla_put_failure;
+
+	return skb->len;
+
+nla_put_failure:
+	nlmsg_trim(skb, b);
+	return -1;
+}
+
+static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
+		      struct Qdisc **old, struct netlink_ext_ack *extack)
+{
+	struct prio_sched_data *q = qdisc_priv(sch);
+	struct tc_prio_qopt_offload graft_offload;
+	unsigned long band = arg - 1;
+
+	if (!new) {
+		new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
+					TC_H_MAKE(sch->handle, arg), extack);
+		if (!new)
+			new = &noop_qdisc;
+		else
+			qdisc_hash_add(new, true);
+	}
+
+	*old = qdisc_replace(sch, new, &q->queues[band]);
+
+	graft_offload.handle = sch->handle;
+	graft_offload.parent = sch->parent;
+	graft_offload.graft_params.band = band;
+	graft_offload.graft_params.child_handle = new->handle;
+	graft_offload.command = TC_PRIO_GRAFT;
+
+	qdisc_offload_graft_helper(qdisc_dev(sch), sch, new, *old,
+				   TC_SETUP_QDISC_PRIO, &graft_offload,
+				   extack);
+	return 0;
+}
+
+static struct Qdisc *
+prio_leaf(struct Qdisc *sch, unsigned long arg)
+{
+	struct prio_sched_data *q = qdisc_priv(sch);
+	unsigned long band = arg - 1;
+
+	return q->queues[band];
+}
+
+static unsigned long prio_find(struct Qdisc *sch, u32 classid)
+{
+	struct prio_sched_data *q = qdisc_priv(sch);
+	unsigned long band = TC_H_MIN(classid);
+
+	if (band - 1 >= q->bands)
+		return 0;
+	return band;
+}
+
+static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
+{
+	return prio_find(sch, classid);
+}
+
+
+static void prio_unbind(struct Qdisc *q, unsigned long cl)
+{
+}
+
+static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
+			   struct tcmsg *tcm)
+{
+	struct prio_sched_data *q = qdisc_priv(sch);
+
+	tcm->tcm_handle |= TC_H_MIN(cl);
+	tcm->tcm_info = q->queues[cl-1]->handle;
+	return 0;
+}
+
+static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
+				 struct gnet_dump *d)
+{
+	struct prio_sched_data *q = qdisc_priv(sch);
+	struct Qdisc *cl_q;
+
+	cl_q = q->queues[cl - 1];
+	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
+				  d, cl_q->cpu_bstats, &cl_q->bstats) < 0 ||
+	    qdisc_qstats_copy(d, cl_q) < 0)
+		return -1;
+
+	return 0;
+}
+
+static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
+{
+	struct prio_sched_data *q = qdisc_priv(sch);
+	int prio;
+
+	if (arg->stop)
+		return;
+
+	for (prio = 0; prio < q->bands; prio++) {
+		if (arg->count < arg->skip) {
+			arg->count++;
+			continue;
+		}
+		if (arg->fn(sch, prio + 1, arg) < 0) {
+			arg->stop = 1;
+			break;
+		}
+		arg->count++;
+	}
+}
+
+static struct tcf_block *prio_tcf_block(struct Qdisc *sch, unsigned long cl,
+					struct netlink_ext_ack *extack)
+{
+	struct prio_sched_data *q = qdisc_priv(sch);
+
+	if (cl)
+		return NULL;
+	return q->block;
+}
+
+static const struct Qdisc_class_ops prio_class_ops = {
+	.graft		=	prio_graft,
+	.leaf		=	prio_leaf,
+	.find		=	prio_find,
+	.walk		=	prio_walk,
+	.tcf_block	=	prio_tcf_block,
+	.bind_tcf	=	prio_bind,
+	.unbind_tcf	=	prio_unbind,
+	.dump		=	prio_dump_class,
+	.dump_stats	=	prio_dump_class_stats,
+};
+
+static struct Qdisc_ops prio_qdisc_ops __read_mostly = {
+	.next		=	NULL,
+	.cl_ops		=	&prio_class_ops,
+	.id		=	"prio",
+	.priv_size	=	sizeof(struct prio_sched_data),
+	.enqueue	=	prio_enqueue,
+	.dequeue	=	prio_dequeue,
+	.peek		=	prio_peek,
+	.init		=	prio_init,
+	.reset		=	prio_reset,
+	.destroy	=	prio_destroy,
+	.change		=	prio_tune,
+	.dump		=	prio_dump,
+	.owner		=	THIS_MODULE,
+};
+
+static int __init prio_module_init(void)
+{
+	return register_qdisc(&prio_qdisc_ops);
+}
+
+static void __exit prio_module_exit(void)
+{
+	unregister_qdisc(&prio_qdisc_ops);
+}
+
+module_init(prio_module_init)
+module_exit(prio_module_exit)
+
+MODULE_LICENSE("GPL");