[deliverable/linux.git] / net / sched / sch_tbf.c

/*
 * net/sched/sch_tbf.c	Token Bucket Filter queue.
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *		Dmitry Torokhov <dtor@mail.ru> - allow attaching inner qdiscs -
 *						 original idea by Martin Devera
 *
 */

#include <linux/module.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>


/*	Simple Token Bucket Filter.
	=======================================

	SOURCE.
	-------

	None.

	Description.
	------------

	A data flow obeys TBF with rate R and depth B, if for any
	time interval t_i...t_f the number of transmitted bits
	does not exceed B + R*(t_f-t_i).

	Packetized version of this definition:
	The sequence of packets of sizes s_i served at moments t_i
	obeys TBF, if for any i<=k:

	s_i+....+s_k <= B + R*(t_k - t_i)

	Algorithm.
	----------

	Let N(t_i) be B/R initially and N(t) grow continuously with time as:

	N(t+delta) = min{B/R, N(t) + delta}

	If the first packet in queue has length S, it may be
	transmitted only at the time t_* when S/R <= N(t_*),
	and in this case N(t) jumps:

	N(t_* + 0) = N(t_* - 0) - S/R.


	Actually, QoS requires two TBF to be applied to a data stream.
	One of them controls steady state burst size, another
	one with rate P (peak rate) and depth M (equal to link MTU)
	limits bursts at a smaller time scale.

	It is easy to see that P>R, and B>M. If P is infinity, this double
	TBF is equivalent to a single one.

	When TBF works in reshaping mode, latency is estimated as:

	lat = max ((L-B)/R, (L-M)/P)


	NOTES.
	------

	If TBF throttles, it starts a watchdog timer, which will wake it up
	when it is ready to transmit.
	Note that the minimal timer resolution is 1/HZ.
	If no new packets arrive during this period,
	or if the device is not awaken by EOI for some previous packet,
	TBF can stop its activity for 1/HZ.


	This means, that with depth B, the maximal rate is

	R_crit = B*HZ

	F.e. for 10Mbit ethernet and HZ=100 the minimal allowed B is ~10Kbytes.

	Note that the peak rate TBF is much more tough: with MTU 1500
	P_crit = 150Kbytes/sec. So, if you need greater peak
	rates, use alpha with HZ=1000 :-)

	With classful TBF, limit is just kept for backwards compatibility.
	It is passed to the default bfifo qdisc - if the inner qdisc is
	changed the limit is not effective anymore.
*/

struct tbf_sched_data
{
/* Parameters */
	u32		limit;		/* Maximal length of backlog: bytes */
	u32		buffer;		/* Token bucket depth/rate: MUST BE >= MTU/B */
	u32		mtu;
	u32		max_size;
	struct qdisc_rate_table	*R_tab;
	struct qdisc_rate_table	*P_tab;

/* Variables */
	long	tokens;			/* Current number of B tokens */
	long	ptokens;		/* Current number of P tokens */
	psched_time_t	t_c;		/* Time check-point */
	struct Qdisc	*qdisc;		/* Inner qdisc, default - bfifo queue */
	struct qdisc_watchdog watchdog;	/* Watchdog timer */
};

#define L2T(q,L)   qdisc_l2t((q)->R_tab,L)
#define L2T_P(q,L) qdisc_l2t((q)->P_tab,L)

static int tbf_enqueue(struct sk_buff *skb, struct Qdisc* sch)
{
	struct tbf_sched_data *q = qdisc_priv(sch);
	int ret;

	if (qdisc_pkt_len(skb) > q->max_size)
		return qdisc_reshape_fail(skb, sch);

	ret = qdisc_enqueue(skb, q->qdisc);
	if (ret != 0) {
		if (net_xmit_drop_count(ret))
			sch->qstats.drops++;
		return ret;
	}

	sch->q.qlen++;
	sch->bstats.bytes += qdisc_pkt_len(skb);
	sch->bstats.packets++;
	return 0;
}

static unsigned int tbf_drop(struct Qdisc* sch)
{
	struct tbf_sched_data *q = qdisc_priv(sch);
	unsigned int len = 0;

	if (q->qdisc->ops->drop && (len = q->qdisc->ops->drop(q->qdisc)) != 0) {
		sch->q.qlen--;
		sch->qstats.drops++;
	}
	return len;
}

static struct sk_buff *tbf_dequeue(struct Qdisc* sch)
{
	struct tbf_sched_data *q = qdisc_priv(sch);
	struct sk_buff *skb;

	skb = q->qdisc->ops->peek(q->qdisc);

	if (skb) {
		psched_time_t now;
		long toks;
		long ptoks = 0;
		unsigned int len = qdisc_pkt_len(skb);

		now = psched_get_time();
		toks = psched_tdiff_bounded(now, q->t_c, q->buffer);

		if (q->P_tab) {
			ptoks = toks + q->ptokens;
			if (ptoks > (long)q->mtu)
				ptoks = q->mtu;
			ptoks -= L2T_P(q, len);
		}
		toks += q->tokens;
		if (toks > (long)q->buffer)
			toks = q->buffer;
		toks -= L2T(q, len);

		if ((toks|ptoks) >= 0) {
			skb = qdisc_dequeue_peeked(q->qdisc);
			if (unlikely(!skb))
				return NULL;

			q->t_c = now;
			q->tokens = toks;
			q->ptokens = ptoks;
			sch->q.qlen--;
			sch->flags &= ~TCQ_F_THROTTLED;
			return skb;
		}

		qdisc_watchdog_schedule(&q->watchdog,
					now + max_t(long, -toks, -ptoks));

		/* Maybe we have a shorter packet in the queue,
		   which can be sent now. It sounds cool,
		   but, however, this is wrong in principle.
		   We MUST NOT reorder packets under these circumstances.

		   Really, if we split the flow into independent
		   subflows, it would be a very good solution.
		   This is the main idea of all FQ algorithms
		   (cf. CSZ, HPFQ, HFSC)
		 */

		sch->qstats.overlimits++;
	}
	return NULL;
}

static void tbf_reset(struct Qdisc* sch)
{
	struct tbf_sched_data *q = qdisc_priv(sch);

	qdisc_reset(q->qdisc);
	sch->q.qlen = 0;
	q->t_c = psched_get_time();
	q->tokens = q->buffer;
	q->ptokens = q->mtu;
	qdisc_watchdog_cancel(&q->watchdog);
}

static const struct nla_policy tbf_policy[TCA_TBF_MAX + 1] = {
	[TCA_TBF_PARMS]	= { .len = sizeof(struct tc_tbf_qopt) },
	[TCA_TBF_RTAB]	= { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
	[TCA_TBF_PTAB]	= { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
};

static int tbf_change(struct Qdisc* sch, struct nlattr *opt)
{
	int err;
	struct tbf_sched_data *q = qdisc_priv(sch);
	struct nlattr *tb[TCA_TBF_PTAB + 1];
	struct tc_tbf_qopt *qopt;
	struct qdisc_rate_table *rtab = NULL;
	struct qdisc_rate_table *ptab = NULL;
	struct qdisc_rate_table *tmp;
	struct Qdisc *child = NULL;
	int max_size,n;

	err = nla_parse_nested(tb, TCA_TBF_PTAB, opt, tbf_policy);
	if (err < 0)
		return err;

	err = -EINVAL;
	if (tb[TCA_TBF_PARMS] == NULL)
		goto done;

	qopt = nla_data(tb[TCA_TBF_PARMS]);
	rtab = qdisc_get_rtab(&qopt->rate, tb[TCA_TBF_RTAB]);
	if (rtab == NULL)
		goto done;

	if (qopt->peakrate.rate) {
		if (qopt->peakrate.rate > qopt->rate.rate)
			ptab = qdisc_get_rtab(&qopt->peakrate, tb[TCA_TBF_PTAB]);
		if (ptab == NULL)
			goto done;
	}

	for (n = 0; n < 256; n++)
		if (rtab->data[n] > qopt->buffer) break;
	max_size = (n << qopt->rate.cell_log)-1;
	if (ptab) {
		int size;

		for (n = 0; n < 256; n++)
			if (ptab->data[n] > qopt->mtu) break;
		size = (n << qopt->peakrate.cell_log)-1;
		if (size < max_size) max_size = size;
	}
	if (max_size < 0)
		goto done;

	if (qopt->limit > 0) {
		child = fifo_create_dflt(sch, &bfifo_qdisc_ops, qopt->limit);
		if (IS_ERR(child)) {
			err = PTR_ERR(child);
			goto done;
		}
	}

	sch_tree_lock(sch);
	if (child) {
		qdisc_tree_decrease_qlen(q->qdisc, q->qdisc->q.qlen);
		qdisc_destroy(q->qdisc);
		q->qdisc = child;
	}
	q->limit = qopt->limit;
	q->mtu = qopt->mtu;
	q->max_size = max_size;
	q->buffer = qopt->buffer;
	q->tokens = q->buffer;
	q->ptokens = q->mtu;

	tmp = q->R_tab;
	q->R_tab = rtab;
	rtab = tmp;

	tmp = q->P_tab;
	q->P_tab = ptab;
	ptab = tmp;
	sch_tree_unlock(sch);
	err = 0;
done:
	if (rtab)
		qdisc_put_rtab(rtab);
	if (ptab)
		qdisc_put_rtab(ptab);
	return err;
}

static int tbf_init(struct Qdisc* sch, struct nlattr *opt)
{
	struct tbf_sched_data *q = qdisc_priv(sch);

	if (opt == NULL)
		return -EINVAL;

	q->t_c = psched_get_time();
	qdisc_watchdog_init(&q->watchdog, sch);
	q->qdisc = &noop_qdisc;

	return tbf_change(sch, opt);
}

static void tbf_destroy(struct Qdisc *sch)
{
	struct tbf_sched_data *q = qdisc_priv(sch);

	qdisc_watchdog_cancel(&q->watchdog);

	if (q->P_tab)
		qdisc_put_rtab(q->P_tab);
	if (q->R_tab)
		qdisc_put_rtab(q->R_tab);

	qdisc_destroy(q->qdisc);
}

static int tbf_dump(struct Qdisc *sch, struct sk_buff *skb)
{
	struct tbf_sched_data *q = qdisc_priv(sch);
	struct nlattr *nest;
	struct tc_tbf_qopt opt;

	nest = nla_nest_start(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;

	opt.limit = q->limit;
	opt.rate = q->R_tab->rate;
	if (q->P_tab)
		opt.peakrate = q->P_tab->rate;
	else
		memset(&opt.peakrate, 0, sizeof(opt.peakrate));
	opt.mtu = q->mtu;
	opt.buffer = q->buffer;
	NLA_PUT(skb, TCA_TBF_PARMS, sizeof(opt), &opt);

	nla_nest_end(skb, nest);
	return skb->len;

nla_put_failure:
	nla_nest_cancel(skb, nest);
	return -1;
}

static int tbf_dump_class(struct Qdisc *sch, unsigned long cl,
			  struct sk_buff *skb, struct tcmsg *tcm)
{
	struct tbf_sched_data *q = qdisc_priv(sch);

	if (cl != 1) 	/* only one class */
		return -ENOENT;

	tcm->tcm_handle |= TC_H_MIN(1);
	tcm->tcm_info = q->qdisc->handle;

	return 0;
}

static int tbf_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
		     struct Qdisc **old)
{
	struct tbf_sched_data *q = qdisc_priv(sch);

	if (new == NULL)
		new = &noop_qdisc;

	sch_tree_lock(sch);
	*old = q->qdisc;
	q->qdisc = new;
	qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
	qdisc_reset(*old);
	sch_tree_unlock(sch);

	return 0;
}

static struct Qdisc *tbf_leaf(struct Qdisc *sch, unsigned long arg)
{
	struct tbf_sched_data *q = qdisc_priv(sch);
	return q->qdisc;
}

static unsigned long tbf_get(struct Qdisc *sch, u32 classid)
{
	return 1;
}

static void tbf_put(struct Qdisc *sch, unsigned long arg)
{
}

static int tbf_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
			    struct nlattr **tca, unsigned long *arg)
{
	return -ENOSYS;
}

static int tbf_delete(struct Qdisc *sch, unsigned long arg)
{
	return -ENOSYS;
}

static void tbf_walk(struct Qdisc *sch, struct qdisc_walker *walker)
{
	if (!walker->stop) {
		if (walker->count >= walker->skip)
			if (walker->fn(sch, 1, walker) < 0) {
				walker->stop = 1;
				return;
			}
		walker->count++;
	}
}

static struct tcf_proto **tbf_find_tcf(struct Qdisc *sch, unsigned long cl)
{
	return NULL;
}

static const struct Qdisc_class_ops tbf_class_ops =
{
	.graft		=	tbf_graft,
	.leaf		=	tbf_leaf,
	.get		=	tbf_get,
	.put		=	tbf_put,
	.change		=	tbf_change_class,
	.delete		=	tbf_delete,
	.walk		=	tbf_walk,
	.tcf_chain	=	tbf_find_tcf,
	.dump		=	tbf_dump_class,
};

static struct Qdisc_ops tbf_qdisc_ops __read_mostly = {
	.next		=	NULL,
	.cl_ops		=	&tbf_class_ops,
	.id		=	"tbf",
	.priv_size	=	sizeof(struct tbf_sched_data),
	.enqueue	=	tbf_enqueue,
	.dequeue	=	tbf_dequeue,
	.peek		=	qdisc_peek_dequeued,
	.drop		=	tbf_drop,
	.init		=	tbf_init,
	.reset		=	tbf_reset,
	.destroy	=	tbf_destroy,
	.change		=	tbf_change,
	.dump		=	tbf_dump,
	.owner		=	THIS_MODULE,
};

static int __init tbf_module_init(void)
{
	return register_qdisc(&tbf_qdisc_ops);
}

static void __exit tbf_module_exit(void)
{
	unregister_qdisc(&tbf_qdisc_ops);
}
module_init(tbf_module_init)
module_exit(tbf_module_exit)
MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* net/sched/sch_tbf.c Token Bucket Filter queue.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation; either version
	7	* 2 of the License, or (at your option) any later version.
	8	*
	9	* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
	10	* Dmitry Torokhov <dtor@mail.ru> - allow attaching inner qdiscs -
	11	* original idea by Martin Devera
	12	*
	13	*/
	14
1da177e4	15	#include <linux/module.h>
1da177e4 LT	16	#include <linux/types.h>
1da177e4 LT	17	#include <linux/kernel.h>
1da177e4	18	#include <linux/string.h>
1da177e4	19	#include <linux/errno.h>
1da177e4	20	#include <linux/skbuff.h>
0ba48053	21	#include <net/netlink.h>
1da177e4 LT	22	#include <net/pkt_sched.h>
	23
	24
	25	/* Simple Token Bucket Filter.
	26	=======================================
	27
	28	SOURCE.
	29	-------
	30
	31	None.
	32
	33	Description.
	34	------------
	35
	36	A data flow obeys TBF with rate R and depth B, if for any
	37	time interval t_i...t_f the number of transmitted bits
	38	does not exceed B + R*(t_f-t_i).
	39
	40	Packetized version of this definition:
	41	The sequence of packets of sizes s_i served at moments t_i
	42	obeys TBF, if for any i<=k:
	43
	44	s_i+....+s_k <= B + R*(t_k - t_i)
	45
	46	Algorithm.
	47	----------
	48
	49	Let N(t_i) be B/R initially and N(t) grow continuously with time as:
	50
	51	N(t+delta) = min{B/R, N(t) + delta}
	52
	53	If the first packet in queue has length S, it may be
	54	transmitted only at the time t_* when S/R <= N(t_*),
	55	and in this case N(t) jumps:
	56
	57	N(t_* + 0) = N(t_* - 0) - S/R.
	58
	59
	60
	61	Actually, QoS requires two TBF to be applied to a data stream.
	62	One of them controls steady state burst size, another
	63	one with rate P (peak rate) and depth M (equal to link MTU)
	64	limits bursts at a smaller time scale.
	65
	66	It is easy to see that P>R, and B>M. If P is infinity, this double
	67	TBF is equivalent to a single one.
	68
	69	When TBF works in reshaping mode, latency is estimated as:
	70
	71	lat = max ((L-B)/R, (L-M)/P)
	72
	73
	74	NOTES.
	75	------
	76
	77	If TBF throttles, it starts a watchdog timer, which will wake it up
	78	when it is ready to transmit.
	79	Note that the minimal timer resolution is 1/HZ.
	80	If no new packets arrive during this period,
	81	or if the device is not awaken by EOI for some previous packet,
	82	TBF can stop its activity for 1/HZ.
	83
	84
	85	This means, that with depth B, the maximal rate is
86
87	R_crit = B*HZ
88
89	F.e. for 10Mbit ethernet and HZ=100 the minimal allowed B is ~10Kbytes.
90
91	Note that the peak rate TBF is much more tough: with MTU 1500
92	P_crit = 150Kbytes/sec. So, if you need greater peak
93	rates, use alpha with HZ=1000 :-)
94
95	With classful TBF, limit is just kept for backwards compatibility.
96	It is passed to the default bfifo qdisc - if the inner qdisc is
97	changed the limit is not effective anymore.
98	*/
99
100	struct tbf_sched_data
101	{
102	/* Parameters */
103	u32 limit; /* Maximal length of backlog: bytes */
104	u32 buffer; /* Token bucket depth/rate: MUST BE >= MTU/B */
105	u32 mtu;
106	u32 max_size;
107	struct qdisc_rate_table *R_tab;
108	struct qdisc_rate_table *P_tab;
109
110	/* Variables */
111	long tokens; /* Current number of B tokens */
112	long ptokens; /* Current number of P tokens */
113	psched_time_t t_c; /* Time check-point */
1da177e4	114	struct Qdisc qdisc; / Inner qdisc, default - bfifo queue */
f7f593e3	115	struct qdisc_watchdog watchdog; /* Watchdog timer */
1da177e4 LT	116	};
1da177e4 LT	117
e9bef55d JDB	118	#define L2T(q,L) qdisc_l2t((q)->R_tab,L)
e9bef55d JDB	119	#define L2T_P(q,L) qdisc_l2t((q)->P_tab,L)
1da177e4 LT	120
	121	static int tbf_enqueue(struct sk_buff skb, struct Qdisc sch)
	122	{
	123	struct tbf_sched_data *q = qdisc_priv(sch);
	124	int ret;
	125
69747650 DM	126	if (qdisc_pkt_len(skb) > q->max_size)
69747650 DM	127	return qdisc_reshape_fail(skb, sch);
1da177e4	128
5f86173b JK	129	ret = qdisc_enqueue(skb, q->qdisc);
5f86173b JK	130	if (ret != 0) {
378a2f09 JP	131	if (net_xmit_drop_count(ret))
378a2f09 JP	132	sch->qstats.drops++;
1da177e4 LT	133	return ret;
	134	}
	135
	136	sch->q.qlen++;
0abf77e5	137	sch->bstats.bytes += qdisc_pkt_len(skb);
1da177e4 LT	138	sch->bstats.packets++;
	139	return 0;
	140	}
	141
1da177e4 LT	142	static unsigned int tbf_drop(struct Qdisc* sch)
	143	{
	144	struct tbf_sched_data *q = qdisc_priv(sch);
6d037a26	145	unsigned int len = 0;
1da177e4	146
6d037a26	147	if (q->qdisc->ops->drop && (len = q->qdisc->ops->drop(q->qdisc)) != 0) {
1da177e4 LT	148	sch->q.qlen--;
	149	sch->qstats.drops++;
	150	}
	151	return len;
	152	}
	153
1da177e4 LT	154	static struct sk_buff tbf_dequeue(struct Qdisc sch)
	155	{
	156	struct tbf_sched_data *q = qdisc_priv(sch);
	157	struct sk_buff *skb;
	158
03c05f0d	159	skb = q->qdisc->ops->peek(q->qdisc);
1da177e4 LT	160
	161	if (skb) {
	162	psched_time_t now;
f7f593e3	163	long toks;
1da177e4	164	long ptoks = 0;
0abf77e5	165	unsigned int len = qdisc_pkt_len(skb);
1da177e4	166
3bebcda2	167	now = psched_get_time();
03cc45c0	168	toks = psched_tdiff_bounded(now, q->t_c, q->buffer);
1da177e4 LT	169
	170	if (q->P_tab) {
	171	ptoks = toks + q->ptokens;
	172	if (ptoks > (long)q->mtu)
	173	ptoks = q->mtu;
	174	ptoks -= L2T_P(q, len);
	175	}
	176	toks += q->tokens;
	177	if (toks > (long)q->buffer)
	178	toks = q->buffer;
	179	toks -= L2T(q, len);
	180
	181	if ((toks\|ptoks) >= 0) {
77be155c	182	skb = qdisc_dequeue_peeked(q->qdisc);
03c05f0d JP	183	if (unlikely(!skb))
	184	return NULL;
	185
1da177e4 LT	186	q->t_c = now;
	187	q->tokens = toks;
	188	q->ptokens = ptoks;
	189	sch->q.qlen--;
	190	sch->flags &= ~TCQ_F_THROTTLED;
	191	return skb;
	192	}
	193
f7f593e3 PM	194	qdisc_watchdog_schedule(&q->watchdog,
f7f593e3 PM	195	now + max_t(long, -toks, -ptoks));
1da177e4 LT	196
	197	/* Maybe we have a shorter packet in the queue,
	198	which can be sent now. It sounds cool,
	199	but, however, this is wrong in principle.
	200	We MUST NOT reorder packets under these circumstances.
	201
	202	Really, if we split the flow into independent
	203	subflows, it would be a very good solution.
	204	This is the main idea of all FQ algorithms
	205	(cf. CSZ, HPFQ, HFSC)
	206	*/
	207
1da177e4 LT	208	sch->qstats.overlimits++;
	209	}
	210	return NULL;
	211	}
	212
	213	static void tbf_reset(struct Qdisc* sch)
	214	{
	215	struct tbf_sched_data *q = qdisc_priv(sch);
	216
	217	qdisc_reset(q->qdisc);
	218	sch->q.qlen = 0;
3bebcda2	219	q->t_c = psched_get_time();
1da177e4 LT	220	q->tokens = q->buffer;
1da177e4 LT	221	q->ptokens = q->mtu;
f7f593e3	222	qdisc_watchdog_cancel(&q->watchdog);
1da177e4 LT	223	}
1da177e4 LT	224
27a3421e PM	225	static const struct nla_policy tbf_policy[TCA_TBF_MAX + 1] = {
	226	[TCA_TBF_PARMS] = { .len = sizeof(struct tc_tbf_qopt) },
	227	[TCA_TBF_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
	228	[TCA_TBF_PTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
	229	};
	230
1e90474c	231	static int tbf_change(struct Qdisc* sch, struct nlattr *opt)
1da177e4	232	{
cee63723	233	int err;
1da177e4	234	struct tbf_sched_data *q = qdisc_priv(sch);
1e90474c	235	struct nlattr *tb[TCA_TBF_PTAB + 1];
1da177e4 LT	236	struct tc_tbf_qopt *qopt;
	237	struct qdisc_rate_table *rtab = NULL;
	238	struct qdisc_rate_table *ptab = NULL;
b94c8afc	239	struct qdisc_rate_table *tmp;
1da177e4 LT	240	struct Qdisc *child = NULL;
	241	int max_size,n;
	242
27a3421e	243	err = nla_parse_nested(tb, TCA_TBF_PTAB, opt, tbf_policy);
cee63723 PM	244	if (err < 0)
	245	return err;
	246
	247	err = -EINVAL;
27a3421e	248	if (tb[TCA_TBF_PARMS] == NULL)
1da177e4 LT	249	goto done;
1da177e4 LT	250
1e90474c PM	251	qopt = nla_data(tb[TCA_TBF_PARMS]);
1e90474c PM	252	rtab = qdisc_get_rtab(&qopt->rate, tb[TCA_TBF_RTAB]);
1da177e4 LT	253	if (rtab == NULL)
	254	goto done;
	255
	256	if (qopt->peakrate.rate) {
	257	if (qopt->peakrate.rate > qopt->rate.rate)
1e90474c	258	ptab = qdisc_get_rtab(&qopt->peakrate, tb[TCA_TBF_PTAB]);
1da177e4 LT	259	if (ptab == NULL)
	260	goto done;
	261	}
	262
	263	for (n = 0; n < 256; n++)
	264	if (rtab->data[n] > qopt->buffer) break;
	265	max_size = (n << qopt->rate.cell_log)-1;
	266	if (ptab) {
	267	int size;
	268
	269	for (n = 0; n < 256; n++)
	270	if (ptab->data[n] > qopt->mtu) break;
	271	size = (n << qopt->peakrate.cell_log)-1;
	272	if (size < max_size) max_size = size;
	273	}
	274	if (max_size < 0)
	275	goto done;
	276
053cfed7	277	if (qopt->limit > 0) {
fb0305ce PM	278	child = fifo_create_dflt(sch, &bfifo_qdisc_ops, qopt->limit);
	279	if (IS_ERR(child)) {
	280	err = PTR_ERR(child);
1da177e4	281	goto done;
fb0305ce	282	}
1da177e4 LT	283	}
	284
	285	sch_tree_lock(sch);
5e50da01 PM	286	if (child) {
5e50da01 PM	287	qdisc_tree_decrease_qlen(q->qdisc, q->qdisc->q.qlen);
b94c8afc PM	288	qdisc_destroy(q->qdisc);
b94c8afc PM	289	q->qdisc = child;
5e50da01	290	}
1da177e4 LT	291	q->limit = qopt->limit;
	292	q->mtu = qopt->mtu;
	293	q->max_size = max_size;
	294	q->buffer = qopt->buffer;
	295	q->tokens = q->buffer;
	296	q->ptokens = q->mtu;
b94c8afc PM	297
	298	tmp = q->R_tab;
	299	q->R_tab = rtab;
	300	rtab = tmp;
	301
	302	tmp = q->P_tab;
	303	q->P_tab = ptab;
	304	ptab = tmp;
1da177e4 LT	305	sch_tree_unlock(sch);
	306	err = 0;
	307	done:
	308	if (rtab)
	309	qdisc_put_rtab(rtab);
	310	if (ptab)
	311	qdisc_put_rtab(ptab);
	312	return err;
	313	}
	314
1e90474c	315	static int tbf_init(struct Qdisc* sch, struct nlattr *opt)
1da177e4 LT	316	{
	317	struct tbf_sched_data *q = qdisc_priv(sch);
	318
	319	if (opt == NULL)
	320	return -EINVAL;
	321
3bebcda2	322	q->t_c = psched_get_time();
f7f593e3	323	qdisc_watchdog_init(&q->watchdog, sch);
1da177e4 LT	324	q->qdisc = &noop_qdisc;
	325
	326	return tbf_change(sch, opt);
	327	}
	328
	329	static void tbf_destroy(struct Qdisc *sch)
	330	{
	331	struct tbf_sched_data *q = qdisc_priv(sch);
	332
f7f593e3	333	qdisc_watchdog_cancel(&q->watchdog);
1da177e4 LT	334
	335	if (q->P_tab)
	336	qdisc_put_rtab(q->P_tab);
	337	if (q->R_tab)
	338	qdisc_put_rtab(q->R_tab);
	339
	340	qdisc_destroy(q->qdisc);
	341	}
	342
	343	static int tbf_dump(struct Qdisc sch, struct sk_buff skb)
	344	{
	345	struct tbf_sched_data *q = qdisc_priv(sch);
4b3550ef	346	struct nlattr *nest;
1da177e4 LT	347	struct tc_tbf_qopt opt;
1da177e4 LT	348
4b3550ef PM	349	nest = nla_nest_start(skb, TCA_OPTIONS);
	350	if (nest == NULL)
	351	goto nla_put_failure;
1da177e4 LT	352
	353	opt.limit = q->limit;
	354	opt.rate = q->R_tab->rate;
	355	if (q->P_tab)
	356	opt.peakrate = q->P_tab->rate;
	357	else
	358	memset(&opt.peakrate, 0, sizeof(opt.peakrate));
	359	opt.mtu = q->mtu;
	360	opt.buffer = q->buffer;
1e90474c	361	NLA_PUT(skb, TCA_TBF_PARMS, sizeof(opt), &opt);
1da177e4	362
4b3550ef	363	nla_nest_end(skb, nest);
1da177e4 LT	364	return skb->len;
1da177e4 LT	365
1e90474c	366	nla_put_failure:
4b3550ef	367	nla_nest_cancel(skb, nest);
1da177e4 LT	368	return -1;
	369	}
	370
	371	static int tbf_dump_class(struct Qdisc *sch, unsigned long cl,
	372	struct sk_buff skb, struct tcmsg tcm)
	373	{
	374	struct tbf_sched_data *q = qdisc_priv(sch);
	375
	376	if (cl != 1) /* only one class */
	377	return -ENOENT;
	378
	379	tcm->tcm_handle \|= TC_H_MIN(1);
	380	tcm->tcm_info = q->qdisc->handle;
	381
	382	return 0;
	383	}
	384
	385	static int tbf_graft(struct Qdisc sch, unsigned long arg, struct Qdisc new,
	386	struct Qdisc **old)
	387	{
	388	struct tbf_sched_data *q = qdisc_priv(sch);
	389
	390	if (new == NULL)
	391	new = &noop_qdisc;
	392
	393	sch_tree_lock(sch);
b94c8afc PM	394	*old = q->qdisc;
b94c8afc PM	395	q->qdisc = new;
5e50da01	396	qdisc_tree_decrease_qlen(old, (old)->q.qlen);
1da177e4	397	qdisc_reset(*old);
1da177e4 LT	398	sch_tree_unlock(sch);
	399
	400	return 0;
	401	}
	402
	403	static struct Qdisc tbf_leaf(struct Qdisc sch, unsigned long arg)
	404	{
	405	struct tbf_sched_data *q = qdisc_priv(sch);
	406	return q->qdisc;
	407	}
	408
	409	static unsigned long tbf_get(struct Qdisc *sch, u32 classid)
	410	{
	411	return 1;
	412	}
	413
	414	static void tbf_put(struct Qdisc *sch, unsigned long arg)
	415	{
	416	}
	417
10297b99	418	static int tbf_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
1e90474c	419	struct nlattr *tca, unsigned long arg)
1da177e4 LT	420	{
	421	return -ENOSYS;
	422	}
	423
	424	static int tbf_delete(struct Qdisc *sch, unsigned long arg)
	425	{
	426	return -ENOSYS;
	427	}
	428
	429	static void tbf_walk(struct Qdisc sch, struct qdisc_walker walker)
	430	{
	431	if (!walker->stop) {
	432	if (walker->count >= walker->skip)
	433	if (walker->fn(sch, 1, walker) < 0) {
	434	walker->stop = 1;
	435	return;
	436	}
	437	walker->count++;
	438	}
	439	}
	440
	441	static struct tcf_proto *tbf_find_tcf(struct Qdisc sch, unsigned long cl)
	442	{
	443	return NULL;
	444	}
	445
20fea08b	446	static const struct Qdisc_class_ops tbf_class_ops =
1da177e4 LT	447	{
	448	.graft = tbf_graft,
	449	.leaf = tbf_leaf,
	450	.get = tbf_get,
	451	.put = tbf_put,
	452	.change = tbf_change_class,
	453	.delete = tbf_delete,
	454	.walk = tbf_walk,
	455	.tcf_chain = tbf_find_tcf,
	456	.dump = tbf_dump_class,
	457	};
	458
20fea08b	459	static struct Qdisc_ops tbf_qdisc_ops __read_mostly = {
1da177e4 LT	460	.next = NULL,
	461	.cl_ops = &tbf_class_ops,
	462	.id = "tbf",
	463	.priv_size = sizeof(struct tbf_sched_data),
	464	.enqueue = tbf_enqueue,
	465	.dequeue = tbf_dequeue,
77be155c	466	.peek = qdisc_peek_dequeued,
1da177e4 LT	467	.drop = tbf_drop,
	468	.init = tbf_init,
	469	.reset = tbf_reset,
	470	.destroy = tbf_destroy,
	471	.change = tbf_change,
	472	.dump = tbf_dump,
	473	.owner = THIS_MODULE,
	474	};
	475
	476	static int __init tbf_module_init(void)
	477	{
	478	return register_qdisc(&tbf_qdisc_ops);
	479	}
	480
	481	static void __exit tbf_module_exit(void)
	482	{
	483	unregister_qdisc(&tbf_qdisc_ops);
	484	}
	485	module_init(tbf_module_init)
	486	module_exit(tbf_module_exit)
	487	MODULE_LICENSE("GPL");