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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
15#include <linux/module.h>
16#include <linux/types.h>
17#include <linux/kernel.h>
18#include <linux/string.h>
19#include <linux/errno.h>
20#include <linux/skbuff.h>
21#include <net/netlink.h>
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
100struct tbf_sched_data {
101/* Parameters */
102 u32 limit; /* Maximal length of backlog: bytes */
103 u32 buffer; /* Token bucket depth/rate: MUST BE >= MTU/B */
104 u32 mtu;
105 u32 max_size;
106 struct qdisc_rate_table *R_tab;
107 struct qdisc_rate_table *P_tab;
108
109/* Variables */
110 long tokens; /* Current number of B tokens */
111 long ptokens; /* Current number of P tokens */
112 psched_time_t t_c; /* Time check-point */
113 struct Qdisc *qdisc; /* Inner qdisc, default - bfifo queue */
114 struct qdisc_watchdog watchdog; /* Watchdog timer */
115};
116
117#define L2T(q, L) qdisc_l2t((q)->R_tab, L)
118#define L2T_P(q, L) qdisc_l2t((q)->P_tab, L)
119
120static int tbf_enqueue(struct sk_buff *skb, struct Qdisc *sch)
121{
122 struct tbf_sched_data *q = qdisc_priv(sch);
123 int ret;
124
125 if (qdisc_pkt_len(skb) > q->max_size)
126 return qdisc_reshape_fail(skb, sch);
127
128 ret = qdisc_enqueue(skb, q->qdisc);
129 if (ret != NET_XMIT_SUCCESS) {
130 if (net_xmit_drop_count(ret))
131 sch->qstats.drops++;
132 return ret;
133 }
134
135 sch->q.qlen++;
136 return NET_XMIT_SUCCESS;
137}
138
139static unsigned int tbf_drop(struct Qdisc *sch)
140{
141 struct tbf_sched_data *q = qdisc_priv(sch);
142 unsigned int len = 0;
143
144 if (q->qdisc->ops->drop && (len = q->qdisc->ops->drop(q->qdisc)) != 0) {
145 sch->q.qlen--;
146 sch->qstats.drops++;
147 }
148 return len;
149}
150
151static struct sk_buff *tbf_dequeue(struct Qdisc *sch)
152{
153 struct tbf_sched_data *q = qdisc_priv(sch);
154 struct sk_buff *skb;
155
156 skb = q->qdisc->ops->peek(q->qdisc);
157
158 if (skb) {
159 psched_time_t now;
160 long toks;
161 long ptoks = 0;
162 unsigned int len = qdisc_pkt_len(skb);
163
164 now = psched_get_time();
165 toks = psched_tdiff_bounded(now, q->t_c, q->buffer);
166
167 if (q->P_tab) {
168 ptoks = toks + q->ptokens;
169 if (ptoks > (long)q->mtu)
170 ptoks = q->mtu;
171 ptoks -= L2T_P(q, len);
172 }
173 toks += q->tokens;
174 if (toks > (long)q->buffer)
175 toks = q->buffer;
176 toks -= L2T(q, len);
177
178 if ((toks|ptoks) >= 0) {
179 skb = qdisc_dequeue_peeked(q->qdisc);
180 if (unlikely(!skb))
181 return NULL;
182
183 q->t_c = now;
184 q->tokens = toks;
185 q->ptokens = ptoks;
186 sch->q.qlen--;
187 qdisc_unthrottled(sch);
188 qdisc_bstats_update(sch, skb);
189 return skb;
190 }
191
192 qdisc_watchdog_schedule(&q->watchdog,
193 now + max_t(long, -toks, -ptoks));
194
195 /* Maybe we have a shorter packet in the queue,
196 which can be sent now. It sounds cool,
197 but, however, this is wrong in principle.
198 We MUST NOT reorder packets under these circumstances.
199
200 Really, if we split the flow into independent
201 subflows, it would be a very good solution.
202 This is the main idea of all FQ algorithms
203 (cf. CSZ, HPFQ, HFSC)
204 */
205
206 sch->qstats.overlimits++;
207 }
208 return NULL;
209}
210
211static void tbf_reset(struct Qdisc *sch)
212{
213 struct tbf_sched_data *q = qdisc_priv(sch);
214
215 qdisc_reset(q->qdisc);
216 sch->q.qlen = 0;
217 q->t_c = psched_get_time();
218 q->tokens = q->buffer;
219 q->ptokens = q->mtu;
220 qdisc_watchdog_cancel(&q->watchdog);
221}
222
223static const struct nla_policy tbf_policy[TCA_TBF_MAX + 1] = {
224 [TCA_TBF_PARMS] = { .len = sizeof(struct tc_tbf_qopt) },
225 [TCA_TBF_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
226 [TCA_TBF_PTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
227};
228
229static int tbf_change(struct Qdisc *sch, struct nlattr *opt)
230{
231 int err;
232 struct tbf_sched_data *q = qdisc_priv(sch);
233 struct nlattr *tb[TCA_TBF_PTAB + 1];
234 struct tc_tbf_qopt *qopt;
235 struct qdisc_rate_table *rtab = NULL;
236 struct qdisc_rate_table *ptab = NULL;
237 struct Qdisc *child = NULL;
238 int max_size, n;
239
240 err = nla_parse_nested(tb, TCA_TBF_PTAB, opt, tbf_policy);
241 if (err < 0)
242 return err;
243
244 err = -EINVAL;
245 if (tb[TCA_TBF_PARMS] == NULL)
246 goto done;
247
248 qopt = nla_data(tb[TCA_TBF_PARMS]);
249 rtab = qdisc_get_rtab(&qopt->rate, tb[TCA_TBF_RTAB]);
250 if (rtab == NULL)
251 goto done;
252
253 if (qopt->peakrate.rate) {
254 if (qopt->peakrate.rate > qopt->rate.rate)
255 ptab = qdisc_get_rtab(&qopt->peakrate, tb[TCA_TBF_PTAB]);
256 if (ptab == NULL)
257 goto done;
258 }
259
260 for (n = 0; n < 256; n++)
261 if (rtab->data[n] > qopt->buffer)
262 break;
263 max_size = (n << qopt->rate.cell_log) - 1;
264 if (ptab) {
265 int size;
266
267 for (n = 0; n < 256; n++)
268 if (ptab->data[n] > qopt->mtu)
269 break;
270 size = (n << qopt->peakrate.cell_log) - 1;
271 if (size < max_size)
272 max_size = size;
273 }
274 if (max_size < 0)
275 goto done;
276
277 if (q->qdisc != &noop_qdisc) {
278 err = fifo_set_limit(q->qdisc, qopt->limit);
279 if (err)
280 goto done;
281 } else if (qopt->limit > 0) {
282 child = fifo_create_dflt(sch, &bfifo_qdisc_ops, qopt->limit);
283 if (IS_ERR(child)) {
284 err = PTR_ERR(child);
285 goto done;
286 }
287 }
288
289 sch_tree_lock(sch);
290 if (child) {
291 qdisc_tree_decrease_qlen(q->qdisc, q->qdisc->q.qlen);
292 qdisc_destroy(q->qdisc);
293 q->qdisc = child;
294 }
295 q->limit = qopt->limit;
296 q->mtu = qopt->mtu;
297 q->max_size = max_size;
298 q->buffer = qopt->buffer;
299 q->tokens = q->buffer;
300 q->ptokens = q->mtu;
301
302 swap(q->R_tab, rtab);
303 swap(q->P_tab, ptab);
304
305 sch_tree_unlock(sch);
306 err = 0;
307done:
308 if (rtab)
309 qdisc_put_rtab(rtab);
310 if (ptab)
311 qdisc_put_rtab(ptab);
312 return err;
313}
314
315static int tbf_init(struct Qdisc *sch, struct nlattr *opt)
316{
317 struct tbf_sched_data *q = qdisc_priv(sch);
318
319 if (opt == NULL)
320 return -EINVAL;
321
322 q->t_c = psched_get_time();
323 qdisc_watchdog_init(&q->watchdog, sch);
324 q->qdisc = &noop_qdisc;
325
326 return tbf_change(sch, opt);
327}
328
329static void tbf_destroy(struct Qdisc *sch)
330{
331 struct tbf_sched_data *q = qdisc_priv(sch);
332
333 qdisc_watchdog_cancel(&q->watchdog);
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
343static int tbf_dump(struct Qdisc *sch, struct sk_buff *skb)
344{
345 struct tbf_sched_data *q = qdisc_priv(sch);
346 struct nlattr *nest;
347 struct tc_tbf_qopt opt;
348
349 sch->qstats.backlog = q->qdisc->qstats.backlog;
350 nest = nla_nest_start(skb, TCA_OPTIONS);
351 if (nest == NULL)
352 goto nla_put_failure;
353
354 opt.limit = q->limit;
355 opt.rate = q->R_tab->rate;
356 if (q->P_tab)
357 opt.peakrate = q->P_tab->rate;
358 else
359 memset(&opt.peakrate, 0, sizeof(opt.peakrate));
360 opt.mtu = q->mtu;
361 opt.buffer = q->buffer;
362 if (nla_put(skb, TCA_TBF_PARMS, sizeof(opt), &opt))
363 goto nla_put_failure;
364
365 nla_nest_end(skb, nest);
366 return skb->len;
367
368nla_put_failure:
369 nla_nest_cancel(skb, nest);
370 return -1;
371}
372
373static int tbf_dump_class(struct Qdisc *sch, unsigned long cl,
374 struct sk_buff *skb, struct tcmsg *tcm)
375{
376 struct tbf_sched_data *q = qdisc_priv(sch);
377
378 tcm->tcm_handle |= TC_H_MIN(1);
379 tcm->tcm_info = q->qdisc->handle;
380
381 return 0;
382}
383
384static int tbf_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
385 struct Qdisc **old)
386{
387 struct tbf_sched_data *q = qdisc_priv(sch);
388
389 if (new == NULL)
390 new = &noop_qdisc;
391
392 sch_tree_lock(sch);
393 *old = q->qdisc;
394 q->qdisc = new;
395 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
396 qdisc_reset(*old);
397 sch_tree_unlock(sch);
398
399 return 0;
400}
401
402static struct Qdisc *tbf_leaf(struct Qdisc *sch, unsigned long arg)
403{
404 struct tbf_sched_data *q = qdisc_priv(sch);
405 return q->qdisc;
406}
407
408static unsigned long tbf_get(struct Qdisc *sch, u32 classid)
409{
410 return 1;
411}
412
413static void tbf_put(struct Qdisc *sch, unsigned long arg)
414{
415}
416
417static void tbf_walk(struct Qdisc *sch, struct qdisc_walker *walker)
418{
419 if (!walker->stop) {
420 if (walker->count >= walker->skip)
421 if (walker->fn(sch, 1, walker) < 0) {
422 walker->stop = 1;
423 return;
424 }
425 walker->count++;
426 }
427}
428
429static const struct Qdisc_class_ops tbf_class_ops = {
430 .graft = tbf_graft,
431 .leaf = tbf_leaf,
432 .get = tbf_get,
433 .put = tbf_put,
434 .walk = tbf_walk,
435 .dump = tbf_dump_class,
436};
437
438static struct Qdisc_ops tbf_qdisc_ops __read_mostly = {
439 .next = NULL,
440 .cl_ops = &tbf_class_ops,
441 .id = "tbf",
442 .priv_size = sizeof(struct tbf_sched_data),
443 .enqueue = tbf_enqueue,
444 .dequeue = tbf_dequeue,
445 .peek = qdisc_peek_dequeued,
446 .drop = tbf_drop,
447 .init = tbf_init,
448 .reset = tbf_reset,
449 .destroy = tbf_destroy,
450 .change = tbf_change,
451 .dump = tbf_dump,
452 .owner = THIS_MODULE,
453};
454
455static int __init tbf_module_init(void)
456{
457 return register_qdisc(&tbf_qdisc_ops);
458}
459
460static void __exit tbf_module_exit(void)
461{
462 unregister_qdisc(&tbf_qdisc_ops);
463}
464module_init(tbf_module_init)
465module_exit(tbf_module_exit)
466MODULE_LICENSE("GPL");
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
15#include <linux/module.h>
16#include <linux/types.h>
17#include <linux/kernel.h>
18#include <linux/string.h>
19#include <linux/errno.h>
20#include <linux/skbuff.h>
21#include <net/netlink.h>
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
100struct tbf_sched_data {
101/* Parameters */
102 u32 limit; /* Maximal length of backlog: bytes */
103 u32 buffer; /* Token bucket depth/rate: MUST BE >= MTU/B */
104 u32 mtu;
105 u32 max_size;
106 struct qdisc_rate_table *R_tab;
107 struct qdisc_rate_table *P_tab;
108
109/* Variables */
110 long tokens; /* Current number of B tokens */
111 long ptokens; /* Current number of P tokens */
112 psched_time_t t_c; /* Time check-point */
113 struct Qdisc *qdisc; /* Inner qdisc, default - bfifo queue */
114 struct qdisc_watchdog watchdog; /* Watchdog timer */
115};
116
117#define L2T(q, L) qdisc_l2t((q)->R_tab, L)
118#define L2T_P(q, L) qdisc_l2t((q)->P_tab, L)
119
120static int tbf_enqueue(struct sk_buff *skb, struct Qdisc *sch)
121{
122 struct tbf_sched_data *q = qdisc_priv(sch);
123 int ret;
124
125 if (qdisc_pkt_len(skb) > q->max_size)
126 return qdisc_reshape_fail(skb, sch);
127
128 ret = qdisc_enqueue(skb, q->qdisc);
129 if (ret != NET_XMIT_SUCCESS) {
130 if (net_xmit_drop_count(ret))
131 sch->qstats.drops++;
132 return ret;
133 }
134
135 sch->q.qlen++;
136 return NET_XMIT_SUCCESS;
137}
138
139static unsigned int tbf_drop(struct Qdisc *sch)
140{
141 struct tbf_sched_data *q = qdisc_priv(sch);
142 unsigned int len = 0;
143
144 if (q->qdisc->ops->drop && (len = q->qdisc->ops->drop(q->qdisc)) != 0) {
145 sch->q.qlen--;
146 sch->qstats.drops++;
147 }
148 return len;
149}
150
151static struct sk_buff *tbf_dequeue(struct Qdisc *sch)
152{
153 struct tbf_sched_data *q = qdisc_priv(sch);
154 struct sk_buff *skb;
155
156 skb = q->qdisc->ops->peek(q->qdisc);
157
158 if (skb) {
159 psched_time_t now;
160 long toks;
161 long ptoks = 0;
162 unsigned int len = qdisc_pkt_len(skb);
163
164 now = psched_get_time();
165 toks = psched_tdiff_bounded(now, q->t_c, q->buffer);
166
167 if (q->P_tab) {
168 ptoks = toks + q->ptokens;
169 if (ptoks > (long)q->mtu)
170 ptoks = q->mtu;
171 ptoks -= L2T_P(q, len);
172 }
173 toks += q->tokens;
174 if (toks > (long)q->buffer)
175 toks = q->buffer;
176 toks -= L2T(q, len);
177
178 if ((toks|ptoks) >= 0) {
179 skb = qdisc_dequeue_peeked(q->qdisc);
180 if (unlikely(!skb))
181 return NULL;
182
183 q->t_c = now;
184 q->tokens = toks;
185 q->ptokens = ptoks;
186 sch->q.qlen--;
187 qdisc_unthrottled(sch);
188 qdisc_bstats_update(sch, skb);
189 return skb;
190 }
191
192 qdisc_watchdog_schedule(&q->watchdog,
193 now + max_t(long, -toks, -ptoks));
194
195 /* Maybe we have a shorter packet in the queue,
196 which can be sent now. It sounds cool,
197 but, however, this is wrong in principle.
198 We MUST NOT reorder packets under these circumstances.
199
200 Really, if we split the flow into independent
201 subflows, it would be a very good solution.
202 This is the main idea of all FQ algorithms
203 (cf. CSZ, HPFQ, HFSC)
204 */
205
206 sch->qstats.overlimits++;
207 }
208 return NULL;
209}
210
211static void tbf_reset(struct Qdisc *sch)
212{
213 struct tbf_sched_data *q = qdisc_priv(sch);
214
215 qdisc_reset(q->qdisc);
216 sch->q.qlen = 0;
217 q->t_c = psched_get_time();
218 q->tokens = q->buffer;
219 q->ptokens = q->mtu;
220 qdisc_watchdog_cancel(&q->watchdog);
221}
222
223static const struct nla_policy tbf_policy[TCA_TBF_MAX + 1] = {
224 [TCA_TBF_PARMS] = { .len = sizeof(struct tc_tbf_qopt) },
225 [TCA_TBF_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
226 [TCA_TBF_PTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
227};
228
229static int tbf_change(struct Qdisc *sch, struct nlattr *opt)
230{
231 int err;
232 struct tbf_sched_data *q = qdisc_priv(sch);
233 struct nlattr *tb[TCA_TBF_PTAB + 1];
234 struct tc_tbf_qopt *qopt;
235 struct qdisc_rate_table *rtab = NULL;
236 struct qdisc_rate_table *ptab = NULL;
237 struct Qdisc *child = NULL;
238 int max_size, n;
239
240 err = nla_parse_nested(tb, TCA_TBF_PTAB, opt, tbf_policy);
241 if (err < 0)
242 return err;
243
244 err = -EINVAL;
245 if (tb[TCA_TBF_PARMS] == NULL)
246 goto done;
247
248 qopt = nla_data(tb[TCA_TBF_PARMS]);
249 rtab = qdisc_get_rtab(&qopt->rate, tb[TCA_TBF_RTAB]);
250 if (rtab == NULL)
251 goto done;
252
253 if (qopt->peakrate.rate) {
254 if (qopt->peakrate.rate > qopt->rate.rate)
255 ptab = qdisc_get_rtab(&qopt->peakrate, tb[TCA_TBF_PTAB]);
256 if (ptab == NULL)
257 goto done;
258 }
259
260 for (n = 0; n < 256; n++)
261 if (rtab->data[n] > qopt->buffer)
262 break;
263 max_size = (n << qopt->rate.cell_log) - 1;
264 if (ptab) {
265 int size;
266
267 for (n = 0; n < 256; n++)
268 if (ptab->data[n] > qopt->mtu)
269 break;
270 size = (n << qopt->peakrate.cell_log) - 1;
271 if (size < max_size)
272 max_size = size;
273 }
274 if (max_size < 0)
275 goto done;
276
277 if (q->qdisc != &noop_qdisc) {
278 err = fifo_set_limit(q->qdisc, qopt->limit);
279 if (err)
280 goto done;
281 } else if (qopt->limit > 0) {
282 child = fifo_create_dflt(sch, &bfifo_qdisc_ops, qopt->limit);
283 if (IS_ERR(child)) {
284 err = PTR_ERR(child);
285 goto done;
286 }
287 }
288
289 sch_tree_lock(sch);
290 if (child) {
291 qdisc_tree_decrease_qlen(q->qdisc, q->qdisc->q.qlen);
292 qdisc_destroy(q->qdisc);
293 q->qdisc = child;
294 }
295 q->limit = qopt->limit;
296 q->mtu = qopt->mtu;
297 q->max_size = max_size;
298 q->buffer = qopt->buffer;
299 q->tokens = q->buffer;
300 q->ptokens = q->mtu;
301
302 swap(q->R_tab, rtab);
303 swap(q->P_tab, ptab);
304
305 sch_tree_unlock(sch);
306 err = 0;
307done:
308 if (rtab)
309 qdisc_put_rtab(rtab);
310 if (ptab)
311 qdisc_put_rtab(ptab);
312 return err;
313}
314
315static int tbf_init(struct Qdisc *sch, struct nlattr *opt)
316{
317 struct tbf_sched_data *q = qdisc_priv(sch);
318
319 if (opt == NULL)
320 return -EINVAL;
321
322 q->t_c = psched_get_time();
323 qdisc_watchdog_init(&q->watchdog, sch);
324 q->qdisc = &noop_qdisc;
325
326 return tbf_change(sch, opt);
327}
328
329static void tbf_destroy(struct Qdisc *sch)
330{
331 struct tbf_sched_data *q = qdisc_priv(sch);
332
333 qdisc_watchdog_cancel(&q->watchdog);
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
343static int tbf_dump(struct Qdisc *sch, struct sk_buff *skb)
344{
345 struct tbf_sched_data *q = qdisc_priv(sch);
346 struct nlattr *nest;
347 struct tc_tbf_qopt opt;
348
349 nest = nla_nest_start(skb, TCA_OPTIONS);
350 if (nest == NULL)
351 goto nla_put_failure;
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;
361 NLA_PUT(skb, TCA_TBF_PARMS, sizeof(opt), &opt);
362
363 nla_nest_end(skb, nest);
364 return skb->len;
365
366nla_put_failure:
367 nla_nest_cancel(skb, nest);
368 return -1;
369}
370
371static 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 tcm->tcm_handle |= TC_H_MIN(1);
377 tcm->tcm_info = q->qdisc->handle;
378
379 return 0;
380}
381
382static int tbf_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
383 struct Qdisc **old)
384{
385 struct tbf_sched_data *q = qdisc_priv(sch);
386
387 if (new == NULL)
388 new = &noop_qdisc;
389
390 sch_tree_lock(sch);
391 *old = q->qdisc;
392 q->qdisc = new;
393 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
394 qdisc_reset(*old);
395 sch_tree_unlock(sch);
396
397 return 0;
398}
399
400static struct Qdisc *tbf_leaf(struct Qdisc *sch, unsigned long arg)
401{
402 struct tbf_sched_data *q = qdisc_priv(sch);
403 return q->qdisc;
404}
405
406static unsigned long tbf_get(struct Qdisc *sch, u32 classid)
407{
408 return 1;
409}
410
411static void tbf_put(struct Qdisc *sch, unsigned long arg)
412{
413}
414
415static void tbf_walk(struct Qdisc *sch, struct qdisc_walker *walker)
416{
417 if (!walker->stop) {
418 if (walker->count >= walker->skip)
419 if (walker->fn(sch, 1, walker) < 0) {
420 walker->stop = 1;
421 return;
422 }
423 walker->count++;
424 }
425}
426
427static const struct Qdisc_class_ops tbf_class_ops = {
428 .graft = tbf_graft,
429 .leaf = tbf_leaf,
430 .get = tbf_get,
431 .put = tbf_put,
432 .walk = tbf_walk,
433 .dump = tbf_dump_class,
434};
435
436static struct Qdisc_ops tbf_qdisc_ops __read_mostly = {
437 .next = NULL,
438 .cl_ops = &tbf_class_ops,
439 .id = "tbf",
440 .priv_size = sizeof(struct tbf_sched_data),
441 .enqueue = tbf_enqueue,
442 .dequeue = tbf_dequeue,
443 .peek = qdisc_peek_dequeued,
444 .drop = tbf_drop,
445 .init = tbf_init,
446 .reset = tbf_reset,
447 .destroy = tbf_destroy,
448 .change = tbf_change,
449 .dump = tbf_dump,
450 .owner = THIS_MODULE,
451};
452
453static int __init tbf_module_init(void)
454{
455 return register_qdisc(&tbf_qdisc_ops);
456}
457
458static void __exit tbf_module_exit(void)
459{
460 unregister_qdisc(&tbf_qdisc_ops);
461}
462module_init(tbf_module_init)
463module_exit(tbf_module_exit)
464MODULE_LICENSE("GPL");