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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/sch_generic.h>
23#include <net/pkt_sched.h>
24
25
26/* Simple Token Bucket Filter.
27 =======================================
28
29 SOURCE.
30 -------
31
32 None.
33
34 Description.
35 ------------
36
37 A data flow obeys TBF with rate R and depth B, if for any
38 time interval t_i...t_f the number of transmitted bits
39 does not exceed B + R*(t_f-t_i).
40
41 Packetized version of this definition:
42 The sequence of packets of sizes s_i served at moments t_i
43 obeys TBF, if for any i<=k:
44
45 s_i+....+s_k <= B + R*(t_k - t_i)
46
47 Algorithm.
48 ----------
49
50 Let N(t_i) be B/R initially and N(t) grow continuously with time as:
51
52 N(t+delta) = min{B/R, N(t) + delta}
53
54 If the first packet in queue has length S, it may be
55 transmitted only at the time t_* when S/R <= N(t_*),
56 and in this case N(t) jumps:
57
58 N(t_* + 0) = N(t_* - 0) - S/R.
59
60
61
62 Actually, QoS requires two TBF to be applied to a data stream.
63 One of them controls steady state burst size, another
64 one with rate P (peak rate) and depth M (equal to link MTU)
65 limits bursts at a smaller time scale.
66
67 It is easy to see that P>R, and B>M. If P is infinity, this double
68 TBF is equivalent to a single one.
69
70 When TBF works in reshaping mode, latency is estimated as:
71
72 lat = max ((L-B)/R, (L-M)/P)
73
74
75 NOTES.
76 ------
77
78 If TBF throttles, it starts a watchdog timer, which will wake it up
79 when it is ready to transmit.
80 Note that the minimal timer resolution is 1/HZ.
81 If no new packets arrive during this period,
82 or if the device is not awaken by EOI for some previous packet,
83 TBF can stop its activity for 1/HZ.
84
85
86 This means, that with depth B, the maximal rate is
87
88 R_crit = B*HZ
89
90 F.e. for 10Mbit ethernet and HZ=100 the minimal allowed B is ~10Kbytes.
91
92 Note that the peak rate TBF is much more tough: with MTU 1500
93 P_crit = 150Kbytes/sec. So, if you need greater peak
94 rates, use alpha with HZ=1000 :-)
95
96 With classful TBF, limit is just kept for backwards compatibility.
97 It is passed to the default bfifo qdisc - if the inner qdisc is
98 changed the limit is not effective anymore.
99*/
100
101struct tbf_sched_data {
102/* Parameters */
103 u32 limit; /* Maximal length of backlog: bytes */
104 u32 max_size;
105 s64 buffer; /* Token bucket depth/rate: MUST BE >= MTU/B */
106 s64 mtu;
107 struct psched_ratecfg rate;
108 struct psched_ratecfg peak;
109
110/* Variables */
111 s64 tokens; /* Current number of B tokens */
112 s64 ptokens; /* Current number of P tokens */
113 s64 t_c; /* Time check-point */
114 struct Qdisc *qdisc; /* Inner qdisc, default - bfifo queue */
115 struct qdisc_watchdog watchdog; /* Watchdog timer */
116};
117
118
119/* Time to Length, convert time in ns to length in bytes
120 * to determinate how many bytes can be sent in given time.
121 */
122static u64 psched_ns_t2l(const struct psched_ratecfg *r,
123 u64 time_in_ns)
124{
125 /* The formula is :
126 * len = (time_in_ns * r->rate_bytes_ps) / NSEC_PER_SEC
127 */
128 u64 len = time_in_ns * r->rate_bytes_ps;
129
130 do_div(len, NSEC_PER_SEC);
131
132 if (unlikely(r->linklayer == TC_LINKLAYER_ATM)) {
133 do_div(len, 53);
134 len = len * 48;
135 }
136
137 if (len > r->overhead)
138 len -= r->overhead;
139 else
140 len = 0;
141
142 return len;
143}
144
145/*
146 * Return length of individual segments of a gso packet,
147 * including all headers (MAC, IP, TCP/UDP)
148 */
149static unsigned int skb_gso_mac_seglen(const struct sk_buff *skb)
150{
151 unsigned int hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
152 return hdr_len + skb_gso_transport_seglen(skb);
153}
154
155/* GSO packet is too big, segment it so that tbf can transmit
156 * each segment in time
157 */
158static int tbf_segment(struct sk_buff *skb, struct Qdisc *sch)
159{
160 struct tbf_sched_data *q = qdisc_priv(sch);
161 struct sk_buff *segs, *nskb;
162 netdev_features_t features = netif_skb_features(skb);
163 int ret, nb;
164
165 segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
166
167 if (IS_ERR_OR_NULL(segs))
168 return qdisc_reshape_fail(skb, sch);
169
170 nb = 0;
171 while (segs) {
172 nskb = segs->next;
173 segs->next = NULL;
174 qdisc_skb_cb(segs)->pkt_len = segs->len;
175 ret = qdisc_enqueue(segs, q->qdisc);
176 if (ret != NET_XMIT_SUCCESS) {
177 if (net_xmit_drop_count(ret))
178 sch->qstats.drops++;
179 } else {
180 nb++;
181 }
182 segs = nskb;
183 }
184 sch->q.qlen += nb;
185 if (nb > 1)
186 qdisc_tree_decrease_qlen(sch, 1 - nb);
187 consume_skb(skb);
188 return nb > 0 ? NET_XMIT_SUCCESS : NET_XMIT_DROP;
189}
190
191static int tbf_enqueue(struct sk_buff *skb, struct Qdisc *sch)
192{
193 struct tbf_sched_data *q = qdisc_priv(sch);
194 int ret;
195
196 if (qdisc_pkt_len(skb) > q->max_size) {
197 if (skb_is_gso(skb) && skb_gso_mac_seglen(skb) <= q->max_size)
198 return tbf_segment(skb, sch);
199 return qdisc_reshape_fail(skb, sch);
200 }
201 ret = qdisc_enqueue(skb, q->qdisc);
202 if (ret != NET_XMIT_SUCCESS) {
203 if (net_xmit_drop_count(ret))
204 sch->qstats.drops++;
205 return ret;
206 }
207
208 sch->q.qlen++;
209 return NET_XMIT_SUCCESS;
210}
211
212static unsigned int tbf_drop(struct Qdisc *sch)
213{
214 struct tbf_sched_data *q = qdisc_priv(sch);
215 unsigned int len = 0;
216
217 if (q->qdisc->ops->drop && (len = q->qdisc->ops->drop(q->qdisc)) != 0) {
218 sch->q.qlen--;
219 sch->qstats.drops++;
220 }
221 return len;
222}
223
224static bool tbf_peak_present(const struct tbf_sched_data *q)
225{
226 return q->peak.rate_bytes_ps;
227}
228
229static struct sk_buff *tbf_dequeue(struct Qdisc *sch)
230{
231 struct tbf_sched_data *q = qdisc_priv(sch);
232 struct sk_buff *skb;
233
234 skb = q->qdisc->ops->peek(q->qdisc);
235
236 if (skb) {
237 s64 now;
238 s64 toks;
239 s64 ptoks = 0;
240 unsigned int len = qdisc_pkt_len(skb);
241
242 now = ktime_to_ns(ktime_get());
243 toks = min_t(s64, now - q->t_c, q->buffer);
244
245 if (tbf_peak_present(q)) {
246 ptoks = toks + q->ptokens;
247 if (ptoks > q->mtu)
248 ptoks = q->mtu;
249 ptoks -= (s64) psched_l2t_ns(&q->peak, len);
250 }
251 toks += q->tokens;
252 if (toks > q->buffer)
253 toks = q->buffer;
254 toks -= (s64) psched_l2t_ns(&q->rate, len);
255
256 if ((toks|ptoks) >= 0) {
257 skb = qdisc_dequeue_peeked(q->qdisc);
258 if (unlikely(!skb))
259 return NULL;
260
261 q->t_c = now;
262 q->tokens = toks;
263 q->ptokens = ptoks;
264 sch->q.qlen--;
265 qdisc_unthrottled(sch);
266 qdisc_bstats_update(sch, skb);
267 return skb;
268 }
269
270 qdisc_watchdog_schedule_ns(&q->watchdog,
271 now + max_t(long, -toks, -ptoks));
272
273 /* Maybe we have a shorter packet in the queue,
274 which can be sent now. It sounds cool,
275 but, however, this is wrong in principle.
276 We MUST NOT reorder packets under these circumstances.
277
278 Really, if we split the flow into independent
279 subflows, it would be a very good solution.
280 This is the main idea of all FQ algorithms
281 (cf. CSZ, HPFQ, HFSC)
282 */
283
284 sch->qstats.overlimits++;
285 }
286 return NULL;
287}
288
289static void tbf_reset(struct Qdisc *sch)
290{
291 struct tbf_sched_data *q = qdisc_priv(sch);
292
293 qdisc_reset(q->qdisc);
294 sch->q.qlen = 0;
295 q->t_c = ktime_to_ns(ktime_get());
296 q->tokens = q->buffer;
297 q->ptokens = q->mtu;
298 qdisc_watchdog_cancel(&q->watchdog);
299}
300
301static const struct nla_policy tbf_policy[TCA_TBF_MAX + 1] = {
302 [TCA_TBF_PARMS] = { .len = sizeof(struct tc_tbf_qopt) },
303 [TCA_TBF_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
304 [TCA_TBF_PTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
305 [TCA_TBF_RATE64] = { .type = NLA_U64 },
306 [TCA_TBF_PRATE64] = { .type = NLA_U64 },
307 [TCA_TBF_BURST] = { .type = NLA_U32 },
308 [TCA_TBF_PBURST] = { .type = NLA_U32 },
309};
310
311static int tbf_change(struct Qdisc *sch, struct nlattr *opt)
312{
313 int err;
314 struct tbf_sched_data *q = qdisc_priv(sch);
315 struct nlattr *tb[TCA_TBF_MAX + 1];
316 struct tc_tbf_qopt *qopt;
317 struct Qdisc *child = NULL;
318 struct psched_ratecfg rate;
319 struct psched_ratecfg peak;
320 u64 max_size;
321 s64 buffer, mtu;
322 u64 rate64 = 0, prate64 = 0;
323
324 err = nla_parse_nested(tb, TCA_TBF_MAX, opt, tbf_policy);
325 if (err < 0)
326 return err;
327
328 err = -EINVAL;
329 if (tb[TCA_TBF_PARMS] == NULL)
330 goto done;
331
332 qopt = nla_data(tb[TCA_TBF_PARMS]);
333 if (qopt->rate.linklayer == TC_LINKLAYER_UNAWARE)
334 qdisc_put_rtab(qdisc_get_rtab(&qopt->rate,
335 tb[TCA_TBF_RTAB]));
336
337 if (qopt->peakrate.linklayer == TC_LINKLAYER_UNAWARE)
338 qdisc_put_rtab(qdisc_get_rtab(&qopt->peakrate,
339 tb[TCA_TBF_PTAB]));
340
341 buffer = min_t(u64, PSCHED_TICKS2NS(qopt->buffer), ~0U);
342 mtu = min_t(u64, PSCHED_TICKS2NS(qopt->mtu), ~0U);
343
344 if (tb[TCA_TBF_RATE64])
345 rate64 = nla_get_u64(tb[TCA_TBF_RATE64]);
346 psched_ratecfg_precompute(&rate, &qopt->rate, rate64);
347
348 if (tb[TCA_TBF_BURST]) {
349 max_size = nla_get_u32(tb[TCA_TBF_BURST]);
350 buffer = psched_l2t_ns(&rate, max_size);
351 } else {
352 max_size = min_t(u64, psched_ns_t2l(&rate, buffer), ~0U);
353 }
354
355 if (qopt->peakrate.rate) {
356 if (tb[TCA_TBF_PRATE64])
357 prate64 = nla_get_u64(tb[TCA_TBF_PRATE64]);
358 psched_ratecfg_precompute(&peak, &qopt->peakrate, prate64);
359 if (peak.rate_bytes_ps <= rate.rate_bytes_ps) {
360 pr_warn_ratelimited("sch_tbf: peakrate %llu is lower than or equals to rate %llu !\n",
361 peak.rate_bytes_ps, rate.rate_bytes_ps);
362 err = -EINVAL;
363 goto done;
364 }
365
366 if (tb[TCA_TBF_PBURST]) {
367 u32 pburst = nla_get_u32(tb[TCA_TBF_PBURST]);
368 max_size = min_t(u32, max_size, pburst);
369 mtu = psched_l2t_ns(&peak, pburst);
370 } else {
371 max_size = min_t(u64, max_size, psched_ns_t2l(&peak, mtu));
372 }
373 } else {
374 memset(&peak, 0, sizeof(peak));
375 }
376
377 if (max_size < psched_mtu(qdisc_dev(sch)))
378 pr_warn_ratelimited("sch_tbf: burst %llu is lower than device %s mtu (%u) !\n",
379 max_size, qdisc_dev(sch)->name,
380 psched_mtu(qdisc_dev(sch)));
381
382 if (!max_size) {
383 err = -EINVAL;
384 goto done;
385 }
386
387 if (q->qdisc != &noop_qdisc) {
388 err = fifo_set_limit(q->qdisc, qopt->limit);
389 if (err)
390 goto done;
391 } else if (qopt->limit > 0) {
392 child = fifo_create_dflt(sch, &bfifo_qdisc_ops, qopt->limit);
393 if (IS_ERR(child)) {
394 err = PTR_ERR(child);
395 goto done;
396 }
397 }
398
399 sch_tree_lock(sch);
400 if (child) {
401 qdisc_tree_decrease_qlen(q->qdisc, q->qdisc->q.qlen);
402 qdisc_destroy(q->qdisc);
403 q->qdisc = child;
404 }
405 q->limit = qopt->limit;
406 if (tb[TCA_TBF_PBURST])
407 q->mtu = mtu;
408 else
409 q->mtu = PSCHED_TICKS2NS(qopt->mtu);
410 q->max_size = max_size;
411 if (tb[TCA_TBF_BURST])
412 q->buffer = buffer;
413 else
414 q->buffer = PSCHED_TICKS2NS(qopt->buffer);
415 q->tokens = q->buffer;
416 q->ptokens = q->mtu;
417
418 memcpy(&q->rate, &rate, sizeof(struct psched_ratecfg));
419 memcpy(&q->peak, &peak, sizeof(struct psched_ratecfg));
420
421 sch_tree_unlock(sch);
422 err = 0;
423done:
424 return err;
425}
426
427static int tbf_init(struct Qdisc *sch, struct nlattr *opt)
428{
429 struct tbf_sched_data *q = qdisc_priv(sch);
430
431 if (opt == NULL)
432 return -EINVAL;
433
434 q->t_c = ktime_to_ns(ktime_get());
435 qdisc_watchdog_init(&q->watchdog, sch);
436 q->qdisc = &noop_qdisc;
437
438 return tbf_change(sch, opt);
439}
440
441static void tbf_destroy(struct Qdisc *sch)
442{
443 struct tbf_sched_data *q = qdisc_priv(sch);
444
445 qdisc_watchdog_cancel(&q->watchdog);
446 qdisc_destroy(q->qdisc);
447}
448
449static int tbf_dump(struct Qdisc *sch, struct sk_buff *skb)
450{
451 struct tbf_sched_data *q = qdisc_priv(sch);
452 struct nlattr *nest;
453 struct tc_tbf_qopt opt;
454
455 sch->qstats.backlog = q->qdisc->qstats.backlog;
456 nest = nla_nest_start(skb, TCA_OPTIONS);
457 if (nest == NULL)
458 goto nla_put_failure;
459
460 opt.limit = q->limit;
461 psched_ratecfg_getrate(&opt.rate, &q->rate);
462 if (tbf_peak_present(q))
463 psched_ratecfg_getrate(&opt.peakrate, &q->peak);
464 else
465 memset(&opt.peakrate, 0, sizeof(opt.peakrate));
466 opt.mtu = PSCHED_NS2TICKS(q->mtu);
467 opt.buffer = PSCHED_NS2TICKS(q->buffer);
468 if (nla_put(skb, TCA_TBF_PARMS, sizeof(opt), &opt))
469 goto nla_put_failure;
470 if (q->rate.rate_bytes_ps >= (1ULL << 32) &&
471 nla_put_u64(skb, TCA_TBF_RATE64, q->rate.rate_bytes_ps))
472 goto nla_put_failure;
473 if (tbf_peak_present(q) &&
474 q->peak.rate_bytes_ps >= (1ULL << 32) &&
475 nla_put_u64(skb, TCA_TBF_PRATE64, q->peak.rate_bytes_ps))
476 goto nla_put_failure;
477
478 return nla_nest_end(skb, nest);
479
480nla_put_failure:
481 nla_nest_cancel(skb, nest);
482 return -1;
483}
484
485static int tbf_dump_class(struct Qdisc *sch, unsigned long cl,
486 struct sk_buff *skb, struct tcmsg *tcm)
487{
488 struct tbf_sched_data *q = qdisc_priv(sch);
489
490 tcm->tcm_handle |= TC_H_MIN(1);
491 tcm->tcm_info = q->qdisc->handle;
492
493 return 0;
494}
495
496static int tbf_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
497 struct Qdisc **old)
498{
499 struct tbf_sched_data *q = qdisc_priv(sch);
500
501 if (new == NULL)
502 new = &noop_qdisc;
503
504 sch_tree_lock(sch);
505 *old = q->qdisc;
506 q->qdisc = new;
507 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
508 qdisc_reset(*old);
509 sch_tree_unlock(sch);
510
511 return 0;
512}
513
514static struct Qdisc *tbf_leaf(struct Qdisc *sch, unsigned long arg)
515{
516 struct tbf_sched_data *q = qdisc_priv(sch);
517 return q->qdisc;
518}
519
520static unsigned long tbf_get(struct Qdisc *sch, u32 classid)
521{
522 return 1;
523}
524
525static void tbf_put(struct Qdisc *sch, unsigned long arg)
526{
527}
528
529static void tbf_walk(struct Qdisc *sch, struct qdisc_walker *walker)
530{
531 if (!walker->stop) {
532 if (walker->count >= walker->skip)
533 if (walker->fn(sch, 1, walker) < 0) {
534 walker->stop = 1;
535 return;
536 }
537 walker->count++;
538 }
539}
540
541static const struct Qdisc_class_ops tbf_class_ops = {
542 .graft = tbf_graft,
543 .leaf = tbf_leaf,
544 .get = tbf_get,
545 .put = tbf_put,
546 .walk = tbf_walk,
547 .dump = tbf_dump_class,
548};
549
550static struct Qdisc_ops tbf_qdisc_ops __read_mostly = {
551 .next = NULL,
552 .cl_ops = &tbf_class_ops,
553 .id = "tbf",
554 .priv_size = sizeof(struct tbf_sched_data),
555 .enqueue = tbf_enqueue,
556 .dequeue = tbf_dequeue,
557 .peek = qdisc_peek_dequeued,
558 .drop = tbf_drop,
559 .init = tbf_init,
560 .reset = tbf_reset,
561 .destroy = tbf_destroy,
562 .change = tbf_change,
563 .dump = tbf_dump,
564 .owner = THIS_MODULE,
565};
566
567static int __init tbf_module_init(void)
568{
569 return register_qdisc(&tbf_qdisc_ops);
570}
571
572static void __exit tbf_module_exit(void)
573{
574 unregister_qdisc(&tbf_qdisc_ops);
575}
576module_init(tbf_module_init)
577module_exit(tbf_module_exit)
578MODULE_LICENSE("GPL");