sch_hfsc.c

linux 内核源代码

	tcf = q->root.filter_list;
	while (tcf && (result = tc_classify(skb, tcf, &res)) >= 0) {
#ifdef CONFIG_NET_CLS_ACT
		switch (result) {
		case TC_ACT_QUEUED:
		case TC_ACT_STOLEN:
			*qerr = NET_XMIT_SUCCESS;
		case TC_ACT_SHOT:
			return NULL;
		}
#endif
		if ((cl = (struct hfsc_class *)res.class) == NULL) {
			if ((cl = hfsc_find_class(res.classid, sch)) == NULL)
				break; /* filter selected invalid classid */
		}

		if (cl->level == 0)
			return cl; /* hit leaf class */

		/* apply inner filter chain */
		tcf = cl->filter_list;
	}

	/* classification failed, try default class */
	cl = hfsc_find_class(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch);
	if (cl == NULL || cl->level > 0)
		return NULL;

	return cl;
}

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

	if (cl == NULL)
		return -ENOENT;
	if (cl->level > 0)
		return -EINVAL;
	if (new == NULL) {
		new = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops,
					cl->classid);
		if (new == NULL)
			new = &noop_qdisc;
	}

	sch_tree_lock(sch);
	hfsc_purge_queue(sch, cl);
	*old = xchg(&cl->qdisc, new);
	sch_tree_unlock(sch);
	return 0;
}

static struct Qdisc *
hfsc_class_leaf(struct Qdisc *sch, unsigned long arg)
{
	struct hfsc_class *cl = (struct hfsc_class *)arg;

	if (cl != NULL && cl->level == 0)
		return cl->qdisc;

	return NULL;
}

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

	if (cl->qdisc->q.qlen == 0) {
		update_vf(cl, 0, 0);
		set_passive(cl);
	}
}

static unsigned long
hfsc_get_class(struct Qdisc *sch, u32 classid)
{
	struct hfsc_class *cl = hfsc_find_class(classid, sch);

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

	return (unsigned long)cl;
}

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

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

static unsigned long
hfsc_bind_tcf(struct Qdisc *sch, unsigned long parent, u32 classid)
{
	struct hfsc_class *p = (struct hfsc_class *)parent;
	struct hfsc_class *cl = hfsc_find_class(classid, sch);

	if (cl != NULL) {
		if (p != NULL && p->level <= cl->level)
			return 0;
		cl->filter_cnt++;
	}

	return (unsigned long)cl;
}

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

	cl->filter_cnt--;
}

static struct tcf_proto **
hfsc_tcf_chain(struct Qdisc *sch, unsigned long arg)
{
	struct hfsc_sched *q = qdisc_priv(sch);
	struct hfsc_class *cl = (struct hfsc_class *)arg;

	if (cl == NULL)
		cl = &q->root;

	return &cl->filter_list;
}

static int
hfsc_dump_sc(struct sk_buff *skb, int attr, struct internal_sc *sc)
{
	struct tc_service_curve tsc;

	tsc.m1 = sm2m(sc->sm1);
	tsc.d  = dx2d(sc->dx);
	tsc.m2 = sm2m(sc->sm2);
	RTA_PUT(skb, attr, sizeof(tsc), &tsc);

	return skb->len;

 rtattr_failure:
	return -1;
}

static inline int
hfsc_dump_curves(struct sk_buff *skb, struct hfsc_class *cl)
{
	if ((cl->cl_flags & HFSC_RSC) &&
	    (hfsc_dump_sc(skb, TCA_HFSC_RSC, &cl->cl_rsc) < 0))
		goto rtattr_failure;

	if ((cl->cl_flags & HFSC_FSC) &&
	    (hfsc_dump_sc(skb, TCA_HFSC_FSC, &cl->cl_fsc) < 0))
		goto rtattr_failure;

	if ((cl->cl_flags & HFSC_USC) &&
	    (hfsc_dump_sc(skb, TCA_HFSC_USC, &cl->cl_usc) < 0))
		goto rtattr_failure;

	return skb->len;

 rtattr_failure:
	return -1;
}

static int
hfsc_dump_class(struct Qdisc *sch, unsigned long arg, struct sk_buff *skb,
		struct tcmsg *tcm)
{
	struct hfsc_class *cl = (struct hfsc_class *)arg;
	unsigned char *b = skb_tail_pointer(skb);
	struct rtattr *rta = (struct rtattr *)b;

	tcm->tcm_parent = cl->cl_parent ? cl->cl_parent->classid : TC_H_ROOT;
	tcm->tcm_handle = cl->classid;
	if (cl->level == 0)
		tcm->tcm_info = cl->qdisc->handle;

	RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
	if (hfsc_dump_curves(skb, cl) < 0)
		goto rtattr_failure;
	rta->rta_len = skb_tail_pointer(skb) - b;
	return skb->len;

 rtattr_failure:
	nlmsg_trim(skb, b);
	return -1;
}

static int
hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
	struct gnet_dump *d)
{
	struct hfsc_class *cl = (struct hfsc_class *)arg;
	struct tc_hfsc_stats xstats;

	cl->qstats.qlen = cl->qdisc->q.qlen;
	xstats.level   = cl->level;
	xstats.period  = cl->cl_vtperiod;
	xstats.work    = cl->cl_total;
	xstats.rtwork  = cl->cl_cumul;

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

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



static void
hfsc_walk(struct Qdisc *sch, struct qdisc_walker *arg)
{
	struct hfsc_sched *q = qdisc_priv(sch);
	struct hfsc_class *cl;
	unsigned int i;

	if (arg->stop)
		return;

	for (i = 0; i < HFSC_HSIZE; i++) {
		list_for_each_entry(cl, &q->clhash[i], hlist) {
			if (arg->count < arg->skip) {
				arg->count++;
				continue;
			}
			if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
				arg->stop = 1;
				return;
			}
			arg->count++;
		}
	}
}

static void
hfsc_schedule_watchdog(struct Qdisc *sch)
{
	struct hfsc_sched *q = qdisc_priv(sch);
	struct hfsc_class *cl;
	u64 next_time = 0;

	if ((cl = eltree_get_minel(q)) != NULL)
		next_time = cl->cl_e;
	if (q->root.cl_cfmin != 0) {
		if (next_time == 0 || next_time > q->root.cl_cfmin)
			next_time = q->root.cl_cfmin;
	}
	WARN_ON(next_time == 0);
	qdisc_watchdog_schedule(&q->watchdog, next_time);
}

static int
hfsc_init_qdisc(struct Qdisc *sch, struct rtattr *opt)
{
	struct hfsc_sched *q = qdisc_priv(sch);
	struct tc_hfsc_qopt *qopt;
	unsigned int i;

	if (opt == NULL || RTA_PAYLOAD(opt) < sizeof(*qopt))
		return -EINVAL;
	qopt = RTA_DATA(opt);

	q->defcls = qopt->defcls;
	for (i = 0; i < HFSC_HSIZE; i++)
		INIT_LIST_HEAD(&q->clhash[i]);
	q->eligible = RB_ROOT;
	INIT_LIST_HEAD(&q->droplist);
	skb_queue_head_init(&q->requeue);

	q->root.refcnt  = 1;
	q->root.classid = sch->handle;
	q->root.sched   = q;
	q->root.qdisc = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops,
					  sch->handle);
	if (q->root.qdisc == NULL)
		q->root.qdisc = &noop_qdisc;
	INIT_LIST_HEAD(&q->root.children);
	q->root.vt_tree = RB_ROOT;
	q->root.cf_tree = RB_ROOT;

	list_add(&q->root.hlist, &q->clhash[hfsc_hash(q->root.classid)]);

	qdisc_watchdog_init(&q->watchdog, sch);

	return 0;
}

static int
hfsc_change_qdisc(struct Qdisc *sch, struct rtattr *opt)
{
	struct hfsc_sched *q = qdisc_priv(sch);
	struct tc_hfsc_qopt *qopt;

	if (opt == NULL || RTA_PAYLOAD(opt) < sizeof(*qopt))
		return -EINVAL;
	qopt = RTA_DATA(opt);

	sch_tree_lock(sch);
	q->defcls = qopt->defcls;
	sch_tree_unlock(sch);

	return 0;
}

static void
hfsc_reset_class(struct hfsc_class *cl)
{
	cl->cl_total        = 0;
	cl->cl_cumul        = 0;
	cl->cl_d            = 0;
	cl->cl_e            = 0;
	cl->cl_vt           = 0;
	cl->cl_vtadj        = 0;
	cl->cl_vtoff        = 0;
	cl->cl_cvtmin       = 0;
	cl->cl_cvtmax       = 0;
	cl->cl_cvtoff       = 0;
	cl->cl_pcvtoff      = 0;
	cl->cl_vtperiod     = 0;
	cl->cl_parentperiod = 0;
	cl->cl_f            = 0;
	cl->cl_myf          = 0;
	cl->cl_myfadj       = 0;
	cl->cl_cfmin        = 0;
	cl->cl_nactive      = 0;

	cl->vt_tree = RB_ROOT;
	cl->cf_tree = RB_ROOT;
	qdisc_reset(cl->qdisc);

	if (cl->cl_flags & HFSC_RSC)
		rtsc_init(&cl->cl_deadline, &cl->cl_rsc, 0, 0);
	if (cl->cl_flags & HFSC_FSC)
		rtsc_init(&cl->cl_virtual, &cl->cl_fsc, 0, 0);
	if (cl->cl_flags & HFSC_USC)
		rtsc_init(&cl->cl_ulimit, &cl->cl_usc, 0, 0);
}

static void
hfsc_reset_qdisc(struct Qdisc *sch)
{
	struct hfsc_sched *q = qdisc_priv(sch);
	struct hfsc_class *cl;
	unsigned int i;

	for (i = 0; i < HFSC_HSIZE; i++) {
		list_for_each_entry(cl, &q->clhash[i], hlist)
			hfsc_reset_class(cl);
	}
	__skb_queue_purge(&q->requeue);
	q->eligible = RB_ROOT;
	INIT_LIST_HEAD(&q->droplist);
	qdisc_watchdog_cancel(&q->watchdog);
	sch->q.qlen = 0;
}

static void
hfsc_destroy_qdisc(struct Qdisc *sch)
{
	struct hfsc_sched *q = qdisc_priv(sch);
	struct hfsc_class *cl, *next;
	unsigned int i;

	for (i = 0; i < HFSC_HSIZE; i++) {
		list_for_each_entry_safe(cl, next, &q->clhash[i], hlist)
			hfsc_destroy_class(sch, cl);
	}
	__skb_queue_purge(&q->requeue);
	qdisc_watchdog_cancel(&q->watchdog);
}

static int
hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb)
{
	struct hfsc_sched *q = qdisc_priv(sch);
	unsigned char *b = skb_tail_pointer(skb);
	struct tc_hfsc_qopt qopt;

	qopt.defcls = q->defcls;
	RTA_PUT(skb, TCA_OPTIONS, sizeof(qopt), &qopt);
	return skb->len;

 rtattr_failure:
	nlmsg_trim(skb, b);
	return -1;
}

static int
hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
	struct hfsc_class *cl;
	unsigned int len;
	int err;

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

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

	if (cl->qdisc->q.qlen == 1)
		set_active(cl, len);

	cl->bstats.packets++;
	cl->bstats.bytes += len;
	sch->bstats.packets++;
	sch->bstats.bytes += len;
	sch->q.qlen++;

	return NET_XMIT_SUCCESS;
}

static struct sk_buff *
hfsc_dequeue(struct Qdisc *sch)
{
	struct hfsc_sched *q = qdisc_priv(sch);
	struct hfsc_class *cl;
	struct sk_buff *skb;
	u64 cur_time;
	unsigned int next_len;
	int realtime = 0;

	if (sch->q.qlen == 0)
		return NULL;
	if ((skb = __skb_dequeue(&q->requeue)))
		goto out;

	cur_time = psched_get_time();

	/*
	 * if there are eligible classes, use real-time criteria.
	 * find the class with the minimum deadline among
	 * the eligible classes.
	 */
	if ((cl = eltree_get_mindl(q, cur_time)) != NULL) {
		realtime = 1;
	} else {
		/*
		 * use link-sharing criteria
		 * get the class with the minimum vt in the hierarchy
		 */
		cl = vttree_get_minvt(&q->root, cur_time);
		if (cl == NULL) {
			sch->qstats.overlimits++;
			hfsc_schedule_watchdog(sch);
			return NULL;
		}
	}

	skb = cl->qdisc->dequeue(cl->qdisc);
	if (skb == NULL) {
		if (net_ratelimit())
			printk("HFSC: Non-work-conserving qdisc ?\n");
		return NULL;
	}

	update_vf(cl, skb->len, cur_time);
	if (realtime)
		cl->cl_cumul += skb->len;

	if (cl->qdisc->q.qlen != 0) {
		if (cl->cl_flags & HFSC_RSC) {
			/* update ed */
			next_len = qdisc_peek_len(cl->qdisc);
			if (realtime)
				update_ed(cl, next_len);
			else
				update_d(cl, next_len);
		}
	} else {
		/* the class becomes passive */
		set_passive(cl);
	}

 out:
	sch->flags &= ~TCQ_F_THROTTLED;
	sch->q.qlen--;

	return skb;
}

static int
hfsc_requeue(struct sk_buff *skb, struct Qdisc *sch)
{
	struct hfsc_sched *q = qdisc_priv(sch);

	__skb_queue_head(&q->requeue, skb);
	sch->q.qlen++;
	sch->qstats.requeues++;
	return NET_XMIT_SUCCESS;
}

static unsigned int
hfsc_drop(struct Qdisc *sch)
{
	struct hfsc_sched *q = qdisc_priv(sch);
	struct hfsc_class *cl;
	unsigned int len;

	list_for_each_entry(cl, &q->droplist, dlist) {
		if (cl->qdisc->ops->drop != NULL &&
		    (len = cl->qdisc->ops->drop(cl->qdisc)) > 0) {
			if (cl->qdisc->q.qlen == 0) {
				update_vf(cl, 0, 0);
				set_passive(cl);
			} else {
				list_move_tail(&cl->dlist, &q->droplist);
			}
			cl->qstats.drops++;
			sch->qstats.drops++;
			sch->q.qlen--;
			return len;
		}
	}
	return 0;
}

static struct Qdisc_class_ops hfsc_class_ops = {
	.change		= hfsc_change_class,
	.delete		= hfsc_delete_class,
	.graft		= hfsc_graft_class,
	.leaf		= hfsc_class_leaf,
	.qlen_notify	= hfsc_qlen_notify,
	.get		= hfsc_get_class,
	.put		= hfsc_put_class,
	.bind_tcf	= hfsc_bind_tcf,
	.unbind_tcf	= hfsc_unbind_tcf,
	.tcf_chain	= hfsc_tcf_chain,
	.dump		= hfsc_dump_class,
	.dump_stats	= hfsc_dump_class_stats,
	.walk		= hfsc_walk
};

static struct Qdisc_ops hfsc_qdisc_ops = {
	.id		= "hfsc",
	.init		= hfsc_init_qdisc,
	.change		= hfsc_change_qdisc,
	.reset		= hfsc_reset_qdisc,
	.destroy	= hfsc_destroy_qdisc,
	.dump		= hfsc_dump_qdisc,
	.enqueue	= hfsc_enqueue,
	.dequeue	= hfsc_dequeue,
	.requeue	= hfsc_requeue,
	.drop		= hfsc_drop,
	.cl_ops		= &hfsc_class_ops,
	.priv_size	= sizeof(struct hfsc_sched),
	.owner		= THIS_MODULE
};

static int __init
hfsc_init(void)
{
	return register_qdisc(&hfsc_qdisc_ops);
}

static void __exit
hfsc_cleanup(void)
{
	unregister_qdisc(&hfsc_qdisc_ops);
}

MODULE_LICENSE("GPL");
module_init(hfsc_init);
module_exit(hfsc_cleanup);