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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// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * net/sched/sch_tbf.c Token Bucket Filter queue.
4 *
5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
6 * Dmitry Torokhov <dtor@mail.ru> - allow attaching inner qdiscs -
7 * original idea by Martin Devera
8 */
9
10#include <linux/module.h>
11#include <linux/types.h>
12#include <linux/kernel.h>
13#include <linux/string.h>
14#include <linux/errno.h>
15#include <linux/skbuff.h>
16#include <net/netlink.h>
17#include <net/sch_generic.h>
18#include <net/pkt_cls.h>
19#include <net/pkt_sched.h>
20
21
22/* Simple Token Bucket Filter.
23 =======================================
24
25 SOURCE.
26 -------
27
28 None.
29
30 Description.
31 ------------
32
33 A data flow obeys TBF with rate R and depth B, if for any
34 time interval t_i...t_f the number of transmitted bits
35 does not exceed B + R*(t_f-t_i).
36
37 Packetized version of this definition:
38 The sequence of packets of sizes s_i served at moments t_i
39 obeys TBF, if for any i<=k:
40
41 s_i+....+s_k <= B + R*(t_k - t_i)
42
43 Algorithm.
44 ----------
45
46 Let N(t_i) be B/R initially and N(t) grow continuously with time as:
47
48 N(t+delta) = min{B/R, N(t) + delta}
49
50 If the first packet in queue has length S, it may be
51 transmitted only at the time t_* when S/R <= N(t_*),
52 and in this case N(t) jumps:
53
54 N(t_* + 0) = N(t_* - 0) - S/R.
55
56
57
58 Actually, QoS requires two TBF to be applied to a data stream.
59 One of them controls steady state burst size, another
60 one with rate P (peak rate) and depth M (equal to link MTU)
61 limits bursts at a smaller time scale.
62
63 It is easy to see that P>R, and B>M. If P is infinity, this double
64 TBF is equivalent to a single one.
65
66 When TBF works in reshaping mode, latency is estimated as:
67
68 lat = max ((L-B)/R, (L-M)/P)
69
70
71 NOTES.
72 ------
73
74 If TBF throttles, it starts a watchdog timer, which will wake it up
75 when it is ready to transmit.
76 Note that the minimal timer resolution is 1/HZ.
77 If no new packets arrive during this period,
78 or if the device is not awaken by EOI for some previous packet,
79 TBF can stop its activity for 1/HZ.
80
81
82 This means, that with depth B, the maximal rate is
83
84 R_crit = B*HZ
85
86 F.e. for 10Mbit ethernet and HZ=100 the minimal allowed B is ~10Kbytes.
87
88 Note that the peak rate TBF is much more tough: with MTU 1500
89 P_crit = 150Kbytes/sec. So, if you need greater peak
90 rates, use alpha with HZ=1000 :-)
91
92 With classful TBF, limit is just kept for backwards compatibility.
93 It is passed to the default bfifo qdisc - if the inner qdisc is
94 changed the limit is not effective anymore.
95*/
96
97struct tbf_sched_data {
98/* Parameters */
99 u32 limit; /* Maximal length of backlog: bytes */
100 u32 max_size;
101 s64 buffer; /* Token bucket depth/rate: MUST BE >= MTU/B */
102 s64 mtu;
103 struct psched_ratecfg rate;
104 struct psched_ratecfg peak;
105
106/* Variables */
107 s64 tokens; /* Current number of B tokens */
108 s64 ptokens; /* Current number of P tokens */
109 s64 t_c; /* Time check-point */
110 struct Qdisc *qdisc; /* Inner qdisc, default - bfifo queue */
111 struct qdisc_watchdog watchdog; /* Watchdog timer */
112};
113
114
115/* Time to Length, convert time in ns to length in bytes
116 * to determinate how many bytes can be sent in given time.
117 */
118static u64 psched_ns_t2l(const struct psched_ratecfg *r,
119 u64 time_in_ns)
120{
121 /* The formula is :
122 * len = (time_in_ns * r->rate_bytes_ps) / NSEC_PER_SEC
123 */
124 u64 len = time_in_ns * r->rate_bytes_ps;
125
126 do_div(len, NSEC_PER_SEC);
127
128 if (unlikely(r->linklayer == TC_LINKLAYER_ATM)) {
129 do_div(len, 53);
130 len = len * 48;
131 }
132
133 if (len > r->overhead)
134 len -= r->overhead;
135 else
136 len = 0;
137
138 return len;
139}
140
141static void tbf_offload_change(struct Qdisc *sch)
142{
143 struct tbf_sched_data *q = qdisc_priv(sch);
144 struct net_device *dev = qdisc_dev(sch);
145 struct tc_tbf_qopt_offload qopt;
146
147 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
148 return;
149
150 qopt.command = TC_TBF_REPLACE;
151 qopt.handle = sch->handle;
152 qopt.parent = sch->parent;
153 qopt.replace_params.rate = q->rate;
154 qopt.replace_params.max_size = q->max_size;
155 qopt.replace_params.qstats = &sch->qstats;
156
157 dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_TBF, &qopt);
158}
159
160static void tbf_offload_destroy(struct Qdisc *sch)
161{
162 struct net_device *dev = qdisc_dev(sch);
163 struct tc_tbf_qopt_offload qopt;
164
165 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
166 return;
167
168 qopt.command = TC_TBF_DESTROY;
169 qopt.handle = sch->handle;
170 qopt.parent = sch->parent;
171 dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_TBF, &qopt);
172}
173
174static int tbf_offload_dump(struct Qdisc *sch)
175{
176 struct tc_tbf_qopt_offload qopt;
177
178 qopt.command = TC_TBF_STATS;
179 qopt.handle = sch->handle;
180 qopt.parent = sch->parent;
181 qopt.stats.bstats = &sch->bstats;
182 qopt.stats.qstats = &sch->qstats;
183
184 return qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_TBF, &qopt);
185}
186
187/* GSO packet is too big, segment it so that tbf can transmit
188 * each segment in time
189 */
190static int tbf_segment(struct sk_buff *skb, struct Qdisc *sch,
191 struct sk_buff **to_free)
192{
193 struct tbf_sched_data *q = qdisc_priv(sch);
194 struct sk_buff *segs, *nskb;
195 netdev_features_t features = netif_skb_features(skb);
196 unsigned int len = 0, prev_len = qdisc_pkt_len(skb);
197 int ret, nb;
198
199 segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
200
201 if (IS_ERR_OR_NULL(segs))
202 return qdisc_drop(skb, sch, to_free);
203
204 nb = 0;
205 skb_list_walk_safe(segs, segs, nskb) {
206 skb_mark_not_on_list(segs);
207 qdisc_skb_cb(segs)->pkt_len = segs->len;
208 len += segs->len;
209 ret = qdisc_enqueue(segs, q->qdisc, to_free);
210 if (ret != NET_XMIT_SUCCESS) {
211 if (net_xmit_drop_count(ret))
212 qdisc_qstats_drop(sch);
213 } else {
214 nb++;
215 }
216 }
217 sch->q.qlen += nb;
218 if (nb > 1)
219 qdisc_tree_reduce_backlog(sch, 1 - nb, prev_len - len);
220 consume_skb(skb);
221 return nb > 0 ? NET_XMIT_SUCCESS : NET_XMIT_DROP;
222}
223
224static int tbf_enqueue(struct sk_buff *skb, struct Qdisc *sch,
225 struct sk_buff **to_free)
226{
227 struct tbf_sched_data *q = qdisc_priv(sch);
228 unsigned int len = qdisc_pkt_len(skb);
229 int ret;
230
231 if (qdisc_pkt_len(skb) > q->max_size) {
232 if (skb_is_gso(skb) &&
233 skb_gso_validate_mac_len(skb, q->max_size))
234 return tbf_segment(skb, sch, to_free);
235 return qdisc_drop(skb, sch, to_free);
236 }
237 ret = qdisc_enqueue(skb, q->qdisc, to_free);
238 if (ret != NET_XMIT_SUCCESS) {
239 if (net_xmit_drop_count(ret))
240 qdisc_qstats_drop(sch);
241 return ret;
242 }
243
244 sch->qstats.backlog += len;
245 sch->q.qlen++;
246 return NET_XMIT_SUCCESS;
247}
248
249static bool tbf_peak_present(const struct tbf_sched_data *q)
250{
251 return q->peak.rate_bytes_ps;
252}
253
254static struct sk_buff *tbf_dequeue(struct Qdisc *sch)
255{
256 struct tbf_sched_data *q = qdisc_priv(sch);
257 struct sk_buff *skb;
258
259 skb = q->qdisc->ops->peek(q->qdisc);
260
261 if (skb) {
262 s64 now;
263 s64 toks;
264 s64 ptoks = 0;
265 unsigned int len = qdisc_pkt_len(skb);
266
267 now = ktime_get_ns();
268 toks = min_t(s64, now - q->t_c, q->buffer);
269
270 if (tbf_peak_present(q)) {
271 ptoks = toks + q->ptokens;
272 if (ptoks > q->mtu)
273 ptoks = q->mtu;
274 ptoks -= (s64) psched_l2t_ns(&q->peak, len);
275 }
276 toks += q->tokens;
277 if (toks > q->buffer)
278 toks = q->buffer;
279 toks -= (s64) psched_l2t_ns(&q->rate, len);
280
281 if ((toks|ptoks) >= 0) {
282 skb = qdisc_dequeue_peeked(q->qdisc);
283 if (unlikely(!skb))
284 return NULL;
285
286 q->t_c = now;
287 q->tokens = toks;
288 q->ptokens = ptoks;
289 qdisc_qstats_backlog_dec(sch, skb);
290 sch->q.qlen--;
291 qdisc_bstats_update(sch, skb);
292 return skb;
293 }
294
295 qdisc_watchdog_schedule_ns(&q->watchdog,
296 now + max_t(long, -toks, -ptoks));
297
298 /* Maybe we have a shorter packet in the queue,
299 which can be sent now. It sounds cool,
300 but, however, this is wrong in principle.
301 We MUST NOT reorder packets under these circumstances.
302
303 Really, if we split the flow into independent
304 subflows, it would be a very good solution.
305 This is the main idea of all FQ algorithms
306 (cf. CSZ, HPFQ, HFSC)
307 */
308
309 qdisc_qstats_overlimit(sch);
310 }
311 return NULL;
312}
313
314static void tbf_reset(struct Qdisc *sch)
315{
316 struct tbf_sched_data *q = qdisc_priv(sch);
317
318 qdisc_reset(q->qdisc);
319 sch->qstats.backlog = 0;
320 sch->q.qlen = 0;
321 q->t_c = ktime_get_ns();
322 q->tokens = q->buffer;
323 q->ptokens = q->mtu;
324 qdisc_watchdog_cancel(&q->watchdog);
325}
326
327static const struct nla_policy tbf_policy[TCA_TBF_MAX + 1] = {
328 [TCA_TBF_PARMS] = { .len = sizeof(struct tc_tbf_qopt) },
329 [TCA_TBF_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
330 [TCA_TBF_PTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
331 [TCA_TBF_RATE64] = { .type = NLA_U64 },
332 [TCA_TBF_PRATE64] = { .type = NLA_U64 },
333 [TCA_TBF_BURST] = { .type = NLA_U32 },
334 [TCA_TBF_PBURST] = { .type = NLA_U32 },
335};
336
337static int tbf_change(struct Qdisc *sch, struct nlattr *opt,
338 struct netlink_ext_ack *extack)
339{
340 int err;
341 struct tbf_sched_data *q = qdisc_priv(sch);
342 struct nlattr *tb[TCA_TBF_MAX + 1];
343 struct tc_tbf_qopt *qopt;
344 struct Qdisc *child = NULL;
345 struct psched_ratecfg rate;
346 struct psched_ratecfg peak;
347 u64 max_size;
348 s64 buffer, mtu;
349 u64 rate64 = 0, prate64 = 0;
350
351 err = nla_parse_nested_deprecated(tb, TCA_TBF_MAX, opt, tbf_policy,
352 NULL);
353 if (err < 0)
354 return err;
355
356 err = -EINVAL;
357 if (tb[TCA_TBF_PARMS] == NULL)
358 goto done;
359
360 qopt = nla_data(tb[TCA_TBF_PARMS]);
361 if (qopt->rate.linklayer == TC_LINKLAYER_UNAWARE)
362 qdisc_put_rtab(qdisc_get_rtab(&qopt->rate,
363 tb[TCA_TBF_RTAB],
364 NULL));
365
366 if (qopt->peakrate.linklayer == TC_LINKLAYER_UNAWARE)
367 qdisc_put_rtab(qdisc_get_rtab(&qopt->peakrate,
368 tb[TCA_TBF_PTAB],
369 NULL));
370
371 buffer = min_t(u64, PSCHED_TICKS2NS(qopt->buffer), ~0U);
372 mtu = min_t(u64, PSCHED_TICKS2NS(qopt->mtu), ~0U);
373
374 if (tb[TCA_TBF_RATE64])
375 rate64 = nla_get_u64(tb[TCA_TBF_RATE64]);
376 psched_ratecfg_precompute(&rate, &qopt->rate, rate64);
377
378 if (tb[TCA_TBF_BURST]) {
379 max_size = nla_get_u32(tb[TCA_TBF_BURST]);
380 buffer = psched_l2t_ns(&rate, max_size);
381 } else {
382 max_size = min_t(u64, psched_ns_t2l(&rate, buffer), ~0U);
383 }
384
385 if (qopt->peakrate.rate) {
386 if (tb[TCA_TBF_PRATE64])
387 prate64 = nla_get_u64(tb[TCA_TBF_PRATE64]);
388 psched_ratecfg_precompute(&peak, &qopt->peakrate, prate64);
389 if (peak.rate_bytes_ps <= rate.rate_bytes_ps) {
390 pr_warn_ratelimited("sch_tbf: peakrate %llu is lower than or equals to rate %llu !\n",
391 peak.rate_bytes_ps, rate.rate_bytes_ps);
392 err = -EINVAL;
393 goto done;
394 }
395
396 if (tb[TCA_TBF_PBURST]) {
397 u32 pburst = nla_get_u32(tb[TCA_TBF_PBURST]);
398 max_size = min_t(u32, max_size, pburst);
399 mtu = psched_l2t_ns(&peak, pburst);
400 } else {
401 max_size = min_t(u64, max_size, psched_ns_t2l(&peak, mtu));
402 }
403 } else {
404 memset(&peak, 0, sizeof(peak));
405 }
406
407 if (max_size < psched_mtu(qdisc_dev(sch)))
408 pr_warn_ratelimited("sch_tbf: burst %llu is lower than device %s mtu (%u) !\n",
409 max_size, qdisc_dev(sch)->name,
410 psched_mtu(qdisc_dev(sch)));
411
412 if (!max_size) {
413 err = -EINVAL;
414 goto done;
415 }
416
417 if (q->qdisc != &noop_qdisc) {
418 err = fifo_set_limit(q->qdisc, qopt->limit);
419 if (err)
420 goto done;
421 } else if (qopt->limit > 0) {
422 child = fifo_create_dflt(sch, &bfifo_qdisc_ops, qopt->limit,
423 extack);
424 if (IS_ERR(child)) {
425 err = PTR_ERR(child);
426 goto done;
427 }
428
429 /* child is fifo, no need to check for noop_qdisc */
430 qdisc_hash_add(child, true);
431 }
432
433 sch_tree_lock(sch);
434 if (child) {
435 qdisc_tree_flush_backlog(q->qdisc);
436 qdisc_put(q->qdisc);
437 q->qdisc = child;
438 }
439 q->limit = qopt->limit;
440 if (tb[TCA_TBF_PBURST])
441 q->mtu = mtu;
442 else
443 q->mtu = PSCHED_TICKS2NS(qopt->mtu);
444 q->max_size = max_size;
445 if (tb[TCA_TBF_BURST])
446 q->buffer = buffer;
447 else
448 q->buffer = PSCHED_TICKS2NS(qopt->buffer);
449 q->tokens = q->buffer;
450 q->ptokens = q->mtu;
451
452 memcpy(&q->rate, &rate, sizeof(struct psched_ratecfg));
453 memcpy(&q->peak, &peak, sizeof(struct psched_ratecfg));
454
455 sch_tree_unlock(sch);
456 err = 0;
457
458 tbf_offload_change(sch);
459done:
460 return err;
461}
462
463static int tbf_init(struct Qdisc *sch, struct nlattr *opt,
464 struct netlink_ext_ack *extack)
465{
466 struct tbf_sched_data *q = qdisc_priv(sch);
467
468 qdisc_watchdog_init(&q->watchdog, sch);
469 q->qdisc = &noop_qdisc;
470
471 if (!opt)
472 return -EINVAL;
473
474 q->t_c = ktime_get_ns();
475
476 return tbf_change(sch, opt, extack);
477}
478
479static void tbf_destroy(struct Qdisc *sch)
480{
481 struct tbf_sched_data *q = qdisc_priv(sch);
482
483 qdisc_watchdog_cancel(&q->watchdog);
484 tbf_offload_destroy(sch);
485 qdisc_put(q->qdisc);
486}
487
488static int tbf_dump(struct Qdisc *sch, struct sk_buff *skb)
489{
490 struct tbf_sched_data *q = qdisc_priv(sch);
491 struct nlattr *nest;
492 struct tc_tbf_qopt opt;
493 int err;
494
495 err = tbf_offload_dump(sch);
496 if (err)
497 return err;
498
499 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
500 if (nest == NULL)
501 goto nla_put_failure;
502
503 opt.limit = q->limit;
504 psched_ratecfg_getrate(&opt.rate, &q->rate);
505 if (tbf_peak_present(q))
506 psched_ratecfg_getrate(&opt.peakrate, &q->peak);
507 else
508 memset(&opt.peakrate, 0, sizeof(opt.peakrate));
509 opt.mtu = PSCHED_NS2TICKS(q->mtu);
510 opt.buffer = PSCHED_NS2TICKS(q->buffer);
511 if (nla_put(skb, TCA_TBF_PARMS, sizeof(opt), &opt))
512 goto nla_put_failure;
513 if (q->rate.rate_bytes_ps >= (1ULL << 32) &&
514 nla_put_u64_64bit(skb, TCA_TBF_RATE64, q->rate.rate_bytes_ps,
515 TCA_TBF_PAD))
516 goto nla_put_failure;
517 if (tbf_peak_present(q) &&
518 q->peak.rate_bytes_ps >= (1ULL << 32) &&
519 nla_put_u64_64bit(skb, TCA_TBF_PRATE64, q->peak.rate_bytes_ps,
520 TCA_TBF_PAD))
521 goto nla_put_failure;
522
523 return nla_nest_end(skb, nest);
524
525nla_put_failure:
526 nla_nest_cancel(skb, nest);
527 return -1;
528}
529
530static int tbf_dump_class(struct Qdisc *sch, unsigned long cl,
531 struct sk_buff *skb, struct tcmsg *tcm)
532{
533 struct tbf_sched_data *q = qdisc_priv(sch);
534
535 tcm->tcm_handle |= TC_H_MIN(1);
536 tcm->tcm_info = q->qdisc->handle;
537
538 return 0;
539}
540
541static int tbf_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
542 struct Qdisc **old, struct netlink_ext_ack *extack)
543{
544 struct tbf_sched_data *q = qdisc_priv(sch);
545
546 if (new == NULL)
547 new = &noop_qdisc;
548
549 *old = qdisc_replace(sch, new, &q->qdisc);
550 return 0;
551}
552
553static struct Qdisc *tbf_leaf(struct Qdisc *sch, unsigned long arg)
554{
555 struct tbf_sched_data *q = qdisc_priv(sch);
556 return q->qdisc;
557}
558
559static unsigned long tbf_find(struct Qdisc *sch, u32 classid)
560{
561 return 1;
562}
563
564static void tbf_walk(struct Qdisc *sch, struct qdisc_walker *walker)
565{
566 if (!walker->stop) {
567 if (walker->count >= walker->skip)
568 if (walker->fn(sch, 1, walker) < 0) {
569 walker->stop = 1;
570 return;
571 }
572 walker->count++;
573 }
574}
575
576static const struct Qdisc_class_ops tbf_class_ops = {
577 .graft = tbf_graft,
578 .leaf = tbf_leaf,
579 .find = tbf_find,
580 .walk = tbf_walk,
581 .dump = tbf_dump_class,
582};
583
584static struct Qdisc_ops tbf_qdisc_ops __read_mostly = {
585 .next = NULL,
586 .cl_ops = &tbf_class_ops,
587 .id = "tbf",
588 .priv_size = sizeof(struct tbf_sched_data),
589 .enqueue = tbf_enqueue,
590 .dequeue = tbf_dequeue,
591 .peek = qdisc_peek_dequeued,
592 .init = tbf_init,
593 .reset = tbf_reset,
594 .destroy = tbf_destroy,
595 .change = tbf_change,
596 .dump = tbf_dump,
597 .owner = THIS_MODULE,
598};
599
600static int __init tbf_module_init(void)
601{
602 return register_qdisc(&tbf_qdisc_ops);
603}
604
605static void __exit tbf_module_exit(void)
606{
607 unregister_qdisc(&tbf_qdisc_ops);
608}
609module_init(tbf_module_init)
610module_exit(tbf_module_exit)
611MODULE_LICENSE("GPL");