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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * net/sched/sch_drr.c Deficit Round Robin scheduler
4 *
5 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
6 */
7
8#include <linux/module.h>
9#include <linux/slab.h>
10#include <linux/init.h>
11#include <linux/errno.h>
12#include <linux/netdevice.h>
13#include <linux/pkt_sched.h>
14#include <net/sch_generic.h>
15#include <net/pkt_sched.h>
16#include <net/pkt_cls.h>
17
18struct drr_class {
19 struct Qdisc_class_common common;
20
21 struct gnet_stats_basic_sync bstats;
22 struct gnet_stats_queue qstats;
23 struct net_rate_estimator __rcu *rate_est;
24 struct list_head alist;
25 struct Qdisc *qdisc;
26
27 u32 quantum;
28 u32 deficit;
29};
30
31struct drr_sched {
32 struct list_head active;
33 struct tcf_proto __rcu *filter_list;
34 struct tcf_block *block;
35 struct Qdisc_class_hash clhash;
36};
37
38static struct drr_class *drr_find_class(struct Qdisc *sch, u32 classid)
39{
40 struct drr_sched *q = qdisc_priv(sch);
41 struct Qdisc_class_common *clc;
42
43 clc = qdisc_class_find(&q->clhash, classid);
44 if (clc == NULL)
45 return NULL;
46 return container_of(clc, struct drr_class, common);
47}
48
49static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
50 [TCA_DRR_QUANTUM] = { .type = NLA_U32 },
51};
52
53static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
54 struct nlattr **tca, unsigned long *arg,
55 struct netlink_ext_ack *extack)
56{
57 struct drr_sched *q = qdisc_priv(sch);
58 struct drr_class *cl = (struct drr_class *)*arg;
59 struct nlattr *opt = tca[TCA_OPTIONS];
60 struct nlattr *tb[TCA_DRR_MAX + 1];
61 u32 quantum;
62 int err;
63
64 if (!opt) {
65 NL_SET_ERR_MSG(extack, "DRR options are required for this operation");
66 return -EINVAL;
67 }
68
69 err = nla_parse_nested_deprecated(tb, TCA_DRR_MAX, opt, drr_policy,
70 extack);
71 if (err < 0)
72 return err;
73
74 if (tb[TCA_DRR_QUANTUM]) {
75 quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
76 if (quantum == 0) {
77 NL_SET_ERR_MSG(extack, "Specified DRR quantum cannot be zero");
78 return -EINVAL;
79 }
80 } else
81 quantum = psched_mtu(qdisc_dev(sch));
82
83 if (cl != NULL) {
84 if (tca[TCA_RATE]) {
85 err = gen_replace_estimator(&cl->bstats, NULL,
86 &cl->rate_est,
87 NULL, true,
88 tca[TCA_RATE]);
89 if (err) {
90 NL_SET_ERR_MSG(extack, "Failed to replace estimator");
91 return err;
92 }
93 }
94
95 sch_tree_lock(sch);
96 if (tb[TCA_DRR_QUANTUM])
97 cl->quantum = quantum;
98 sch_tree_unlock(sch);
99
100 return 0;
101 }
102
103 cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
104 if (cl == NULL)
105 return -ENOBUFS;
106
107 gnet_stats_basic_sync_init(&cl->bstats);
108 cl->common.classid = classid;
109 cl->quantum = quantum;
110 cl->qdisc = qdisc_create_dflt(sch->dev_queue,
111 &pfifo_qdisc_ops, classid,
112 NULL);
113 if (cl->qdisc == NULL)
114 cl->qdisc = &noop_qdisc;
115 else
116 qdisc_hash_add(cl->qdisc, true);
117
118 if (tca[TCA_RATE]) {
119 err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est,
120 NULL, true, tca[TCA_RATE]);
121 if (err) {
122 NL_SET_ERR_MSG(extack, "Failed to replace estimator");
123 qdisc_put(cl->qdisc);
124 kfree(cl);
125 return err;
126 }
127 }
128
129 sch_tree_lock(sch);
130 qdisc_class_hash_insert(&q->clhash, &cl->common);
131 sch_tree_unlock(sch);
132
133 qdisc_class_hash_grow(sch, &q->clhash);
134
135 *arg = (unsigned long)cl;
136 return 0;
137}
138
139static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl)
140{
141 gen_kill_estimator(&cl->rate_est);
142 qdisc_put(cl->qdisc);
143 kfree(cl);
144}
145
146static int drr_delete_class(struct Qdisc *sch, unsigned long arg,
147 struct netlink_ext_ack *extack)
148{
149 struct drr_sched *q = qdisc_priv(sch);
150 struct drr_class *cl = (struct drr_class *)arg;
151
152 if (qdisc_class_in_use(&cl->common)) {
153 NL_SET_ERR_MSG(extack, "DRR class is in use");
154 return -EBUSY;
155 }
156
157 sch_tree_lock(sch);
158
159 qdisc_purge_queue(cl->qdisc);
160 qdisc_class_hash_remove(&q->clhash, &cl->common);
161
162 sch_tree_unlock(sch);
163
164 drr_destroy_class(sch, cl);
165 return 0;
166}
167
168static unsigned long drr_search_class(struct Qdisc *sch, u32 classid)
169{
170 return (unsigned long)drr_find_class(sch, classid);
171}
172
173static struct tcf_block *drr_tcf_block(struct Qdisc *sch, unsigned long cl,
174 struct netlink_ext_ack *extack)
175{
176 struct drr_sched *q = qdisc_priv(sch);
177
178 if (cl) {
179 NL_SET_ERR_MSG(extack, "DRR classid must be zero");
180 return NULL;
181 }
182
183 return q->block;
184}
185
186static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
187 u32 classid)
188{
189 struct drr_class *cl = drr_find_class(sch, classid);
190
191 if (cl)
192 qdisc_class_get(&cl->common);
193
194 return (unsigned long)cl;
195}
196
197static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
198{
199 struct drr_class *cl = (struct drr_class *)arg;
200
201 qdisc_class_put(&cl->common);
202}
203
204static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
205 struct Qdisc *new, struct Qdisc **old,
206 struct netlink_ext_ack *extack)
207{
208 struct drr_class *cl = (struct drr_class *)arg;
209
210 if (new == NULL) {
211 new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
212 cl->common.classid, NULL);
213 if (new == NULL)
214 new = &noop_qdisc;
215 }
216
217 *old = qdisc_replace(sch, new, &cl->qdisc);
218 return 0;
219}
220
221static struct Qdisc *drr_class_leaf(struct Qdisc *sch, unsigned long arg)
222{
223 struct drr_class *cl = (struct drr_class *)arg;
224
225 return cl->qdisc;
226}
227
228static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
229{
230 struct drr_class *cl = (struct drr_class *)arg;
231
232 list_del(&cl->alist);
233}
234
235static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
236 struct sk_buff *skb, struct tcmsg *tcm)
237{
238 struct drr_class *cl = (struct drr_class *)arg;
239 struct nlattr *nest;
240
241 tcm->tcm_parent = TC_H_ROOT;
242 tcm->tcm_handle = cl->common.classid;
243 tcm->tcm_info = cl->qdisc->handle;
244
245 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
246 if (nest == NULL)
247 goto nla_put_failure;
248 if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
249 goto nla_put_failure;
250 return nla_nest_end(skb, nest);
251
252nla_put_failure:
253 nla_nest_cancel(skb, nest);
254 return -EMSGSIZE;
255}
256
257static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
258 struct gnet_dump *d)
259{
260 struct drr_class *cl = (struct drr_class *)arg;
261 __u32 qlen = qdisc_qlen_sum(cl->qdisc);
262 struct Qdisc *cl_q = cl->qdisc;
263 struct tc_drr_stats xstats;
264
265 memset(&xstats, 0, sizeof(xstats));
266 if (qlen)
267 xstats.deficit = cl->deficit;
268
269 if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 ||
270 gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
271 gnet_stats_copy_queue(d, cl_q->cpu_qstats, &cl_q->qstats, qlen) < 0)
272 return -1;
273
274 return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
275}
276
277static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg)
278{
279 struct drr_sched *q = qdisc_priv(sch);
280 struct drr_class *cl;
281 unsigned int i;
282
283 if (arg->stop)
284 return;
285
286 for (i = 0; i < q->clhash.hashsize; i++) {
287 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
288 if (!tc_qdisc_stats_dump(sch, (unsigned long)cl, arg))
289 return;
290 }
291 }
292}
293
294static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
295 int *qerr)
296{
297 struct drr_sched *q = qdisc_priv(sch);
298 struct drr_class *cl;
299 struct tcf_result res;
300 struct tcf_proto *fl;
301 int result;
302
303 if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
304 cl = drr_find_class(sch, skb->priority);
305 if (cl != NULL)
306 return cl;
307 }
308
309 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
310 fl = rcu_dereference_bh(q->filter_list);
311 result = tcf_classify(skb, NULL, fl, &res, false);
312 if (result >= 0) {
313#ifdef CONFIG_NET_CLS_ACT
314 switch (result) {
315 case TC_ACT_QUEUED:
316 case TC_ACT_STOLEN:
317 case TC_ACT_TRAP:
318 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
319 fallthrough;
320 case TC_ACT_SHOT:
321 return NULL;
322 }
323#endif
324 cl = (struct drr_class *)res.class;
325 if (cl == NULL)
326 cl = drr_find_class(sch, res.classid);
327 return cl;
328 }
329 return NULL;
330}
331
332static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch,
333 struct sk_buff **to_free)
334{
335 unsigned int len = qdisc_pkt_len(skb);
336 struct drr_sched *q = qdisc_priv(sch);
337 struct drr_class *cl;
338 int err = 0;
339 bool first;
340
341 cl = drr_classify(skb, sch, &err);
342 if (cl == NULL) {
343 if (err & __NET_XMIT_BYPASS)
344 qdisc_qstats_drop(sch);
345 __qdisc_drop(skb, to_free);
346 return err;
347 }
348
349 first = !cl->qdisc->q.qlen;
350 err = qdisc_enqueue(skb, cl->qdisc, to_free);
351 if (unlikely(err != NET_XMIT_SUCCESS)) {
352 if (net_xmit_drop_count(err)) {
353 cl->qstats.drops++;
354 qdisc_qstats_drop(sch);
355 }
356 return err;
357 }
358
359 if (first) {
360 list_add_tail(&cl->alist, &q->active);
361 cl->deficit = cl->quantum;
362 }
363
364 sch->qstats.backlog += len;
365 sch->q.qlen++;
366 return err;
367}
368
369static struct sk_buff *drr_dequeue(struct Qdisc *sch)
370{
371 struct drr_sched *q = qdisc_priv(sch);
372 struct drr_class *cl;
373 struct sk_buff *skb;
374 unsigned int len;
375
376 if (list_empty(&q->active))
377 goto out;
378 while (1) {
379 cl = list_first_entry(&q->active, struct drr_class, alist);
380 skb = cl->qdisc->ops->peek(cl->qdisc);
381 if (skb == NULL) {
382 qdisc_warn_nonwc(__func__, cl->qdisc);
383 goto out;
384 }
385
386 len = qdisc_pkt_len(skb);
387 if (len <= cl->deficit) {
388 cl->deficit -= len;
389 skb = qdisc_dequeue_peeked(cl->qdisc);
390 if (unlikely(skb == NULL))
391 goto out;
392 if (cl->qdisc->q.qlen == 0)
393 list_del(&cl->alist);
394
395 bstats_update(&cl->bstats, skb);
396 qdisc_bstats_update(sch, skb);
397 qdisc_qstats_backlog_dec(sch, skb);
398 sch->q.qlen--;
399 return skb;
400 }
401
402 cl->deficit += cl->quantum;
403 list_move_tail(&cl->alist, &q->active);
404 }
405out:
406 return NULL;
407}
408
409static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt,
410 struct netlink_ext_ack *extack)
411{
412 struct drr_sched *q = qdisc_priv(sch);
413 int err;
414
415 err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
416 if (err)
417 return err;
418 err = qdisc_class_hash_init(&q->clhash);
419 if (err < 0)
420 return err;
421 INIT_LIST_HEAD(&q->active);
422 return 0;
423}
424
425static void drr_reset_qdisc(struct Qdisc *sch)
426{
427 struct drr_sched *q = qdisc_priv(sch);
428 struct drr_class *cl;
429 unsigned int i;
430
431 for (i = 0; i < q->clhash.hashsize; i++) {
432 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
433 if (cl->qdisc->q.qlen)
434 list_del(&cl->alist);
435 qdisc_reset(cl->qdisc);
436 }
437 }
438}
439
440static void drr_destroy_qdisc(struct Qdisc *sch)
441{
442 struct drr_sched *q = qdisc_priv(sch);
443 struct drr_class *cl;
444 struct hlist_node *next;
445 unsigned int i;
446
447 tcf_block_put(q->block);
448
449 for (i = 0; i < q->clhash.hashsize; i++) {
450 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
451 common.hnode)
452 drr_destroy_class(sch, cl);
453 }
454 qdisc_class_hash_destroy(&q->clhash);
455}
456
457static const struct Qdisc_class_ops drr_class_ops = {
458 .change = drr_change_class,
459 .delete = drr_delete_class,
460 .find = drr_search_class,
461 .tcf_block = drr_tcf_block,
462 .bind_tcf = drr_bind_tcf,
463 .unbind_tcf = drr_unbind_tcf,
464 .graft = drr_graft_class,
465 .leaf = drr_class_leaf,
466 .qlen_notify = drr_qlen_notify,
467 .dump = drr_dump_class,
468 .dump_stats = drr_dump_class_stats,
469 .walk = drr_walk,
470};
471
472static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
473 .cl_ops = &drr_class_ops,
474 .id = "drr",
475 .priv_size = sizeof(struct drr_sched),
476 .enqueue = drr_enqueue,
477 .dequeue = drr_dequeue,
478 .peek = qdisc_peek_dequeued,
479 .init = drr_init_qdisc,
480 .reset = drr_reset_qdisc,
481 .destroy = drr_destroy_qdisc,
482 .owner = THIS_MODULE,
483};
484MODULE_ALIAS_NET_SCH("drr");
485
486static int __init drr_init(void)
487{
488 return register_qdisc(&drr_qdisc_ops);
489}
490
491static void __exit drr_exit(void)
492{
493 unregister_qdisc(&drr_qdisc_ops);
494}
495
496module_init(drr_init);
497module_exit(drr_exit);
498MODULE_LICENSE("GPL");
499MODULE_DESCRIPTION("Deficit Round Robin scheduler");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * net/sched/sch_drr.c Deficit Round Robin scheduler
4 *
5 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
6 */
7
8#include <linux/module.h>
9#include <linux/slab.h>
10#include <linux/init.h>
11#include <linux/errno.h>
12#include <linux/netdevice.h>
13#include <linux/pkt_sched.h>
14#include <net/sch_generic.h>
15#include <net/pkt_sched.h>
16#include <net/pkt_cls.h>
17
18struct drr_class {
19 struct Qdisc_class_common common;
20 unsigned int filter_cnt;
21
22 struct gnet_stats_basic_sync bstats;
23 struct gnet_stats_queue qstats;
24 struct net_rate_estimator __rcu *rate_est;
25 struct list_head alist;
26 struct Qdisc *qdisc;
27
28 u32 quantum;
29 u32 deficit;
30};
31
32struct drr_sched {
33 struct list_head active;
34 struct tcf_proto __rcu *filter_list;
35 struct tcf_block *block;
36 struct Qdisc_class_hash clhash;
37};
38
39static struct drr_class *drr_find_class(struct Qdisc *sch, u32 classid)
40{
41 struct drr_sched *q = qdisc_priv(sch);
42 struct Qdisc_class_common *clc;
43
44 clc = qdisc_class_find(&q->clhash, classid);
45 if (clc == NULL)
46 return NULL;
47 return container_of(clc, struct drr_class, common);
48}
49
50static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
51 [TCA_DRR_QUANTUM] = { .type = NLA_U32 },
52};
53
54static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
55 struct nlattr **tca, unsigned long *arg,
56 struct netlink_ext_ack *extack)
57{
58 struct drr_sched *q = qdisc_priv(sch);
59 struct drr_class *cl = (struct drr_class *)*arg;
60 struct nlattr *opt = tca[TCA_OPTIONS];
61 struct nlattr *tb[TCA_DRR_MAX + 1];
62 u32 quantum;
63 int err;
64
65 if (!opt) {
66 NL_SET_ERR_MSG(extack, "DRR options are required for this operation");
67 return -EINVAL;
68 }
69
70 err = nla_parse_nested_deprecated(tb, TCA_DRR_MAX, opt, drr_policy,
71 extack);
72 if (err < 0)
73 return err;
74
75 if (tb[TCA_DRR_QUANTUM]) {
76 quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
77 if (quantum == 0) {
78 NL_SET_ERR_MSG(extack, "Specified DRR quantum cannot be zero");
79 return -EINVAL;
80 }
81 } else
82 quantum = psched_mtu(qdisc_dev(sch));
83
84 if (cl != NULL) {
85 if (tca[TCA_RATE]) {
86 err = gen_replace_estimator(&cl->bstats, NULL,
87 &cl->rate_est,
88 NULL, true,
89 tca[TCA_RATE]);
90 if (err) {
91 NL_SET_ERR_MSG(extack, "Failed to replace estimator");
92 return err;
93 }
94 }
95
96 sch_tree_lock(sch);
97 if (tb[TCA_DRR_QUANTUM])
98 cl->quantum = quantum;
99 sch_tree_unlock(sch);
100
101 return 0;
102 }
103
104 cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
105 if (cl == NULL)
106 return -ENOBUFS;
107
108 gnet_stats_basic_sync_init(&cl->bstats);
109 cl->common.classid = classid;
110 cl->quantum = quantum;
111 cl->qdisc = qdisc_create_dflt(sch->dev_queue,
112 &pfifo_qdisc_ops, classid,
113 NULL);
114 if (cl->qdisc == NULL)
115 cl->qdisc = &noop_qdisc;
116 else
117 qdisc_hash_add(cl->qdisc, true);
118
119 if (tca[TCA_RATE]) {
120 err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est,
121 NULL, true, tca[TCA_RATE]);
122 if (err) {
123 NL_SET_ERR_MSG(extack, "Failed to replace estimator");
124 qdisc_put(cl->qdisc);
125 kfree(cl);
126 return err;
127 }
128 }
129
130 sch_tree_lock(sch);
131 qdisc_class_hash_insert(&q->clhash, &cl->common);
132 sch_tree_unlock(sch);
133
134 qdisc_class_hash_grow(sch, &q->clhash);
135
136 *arg = (unsigned long)cl;
137 return 0;
138}
139
140static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl)
141{
142 gen_kill_estimator(&cl->rate_est);
143 qdisc_put(cl->qdisc);
144 kfree(cl);
145}
146
147static int drr_delete_class(struct Qdisc *sch, unsigned long arg,
148 struct netlink_ext_ack *extack)
149{
150 struct drr_sched *q = qdisc_priv(sch);
151 struct drr_class *cl = (struct drr_class *)arg;
152
153 if (cl->filter_cnt > 0)
154 return -EBUSY;
155
156 sch_tree_lock(sch);
157
158 qdisc_purge_queue(cl->qdisc);
159 qdisc_class_hash_remove(&q->clhash, &cl->common);
160
161 sch_tree_unlock(sch);
162
163 drr_destroy_class(sch, cl);
164 return 0;
165}
166
167static unsigned long drr_search_class(struct Qdisc *sch, u32 classid)
168{
169 return (unsigned long)drr_find_class(sch, classid);
170}
171
172static struct tcf_block *drr_tcf_block(struct Qdisc *sch, unsigned long cl,
173 struct netlink_ext_ack *extack)
174{
175 struct drr_sched *q = qdisc_priv(sch);
176
177 if (cl) {
178 NL_SET_ERR_MSG(extack, "DRR classid must be zero");
179 return NULL;
180 }
181
182 return q->block;
183}
184
185static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
186 u32 classid)
187{
188 struct drr_class *cl = drr_find_class(sch, classid);
189
190 if (cl != NULL)
191 cl->filter_cnt++;
192
193 return (unsigned long)cl;
194}
195
196static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
197{
198 struct drr_class *cl = (struct drr_class *)arg;
199
200 cl->filter_cnt--;
201}
202
203static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
204 struct Qdisc *new, struct Qdisc **old,
205 struct netlink_ext_ack *extack)
206{
207 struct drr_class *cl = (struct drr_class *)arg;
208
209 if (new == NULL) {
210 new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
211 cl->common.classid, NULL);
212 if (new == NULL)
213 new = &noop_qdisc;
214 }
215
216 *old = qdisc_replace(sch, new, &cl->qdisc);
217 return 0;
218}
219
220static struct Qdisc *drr_class_leaf(struct Qdisc *sch, unsigned long arg)
221{
222 struct drr_class *cl = (struct drr_class *)arg;
223
224 return cl->qdisc;
225}
226
227static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
228{
229 struct drr_class *cl = (struct drr_class *)arg;
230
231 list_del(&cl->alist);
232}
233
234static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
235 struct sk_buff *skb, struct tcmsg *tcm)
236{
237 struct drr_class *cl = (struct drr_class *)arg;
238 struct nlattr *nest;
239
240 tcm->tcm_parent = TC_H_ROOT;
241 tcm->tcm_handle = cl->common.classid;
242 tcm->tcm_info = cl->qdisc->handle;
243
244 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
245 if (nest == NULL)
246 goto nla_put_failure;
247 if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
248 goto nla_put_failure;
249 return nla_nest_end(skb, nest);
250
251nla_put_failure:
252 nla_nest_cancel(skb, nest);
253 return -EMSGSIZE;
254}
255
256static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
257 struct gnet_dump *d)
258{
259 struct drr_class *cl = (struct drr_class *)arg;
260 __u32 qlen = qdisc_qlen_sum(cl->qdisc);
261 struct Qdisc *cl_q = cl->qdisc;
262 struct tc_drr_stats xstats;
263
264 memset(&xstats, 0, sizeof(xstats));
265 if (qlen)
266 xstats.deficit = cl->deficit;
267
268 if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 ||
269 gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
270 gnet_stats_copy_queue(d, cl_q->cpu_qstats, &cl_q->qstats, qlen) < 0)
271 return -1;
272
273 return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
274}
275
276static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg)
277{
278 struct drr_sched *q = qdisc_priv(sch);
279 struct drr_class *cl;
280 unsigned int i;
281
282 if (arg->stop)
283 return;
284
285 for (i = 0; i < q->clhash.hashsize; i++) {
286 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
287 if (!tc_qdisc_stats_dump(sch, (unsigned long)cl, arg))
288 return;
289 }
290 }
291}
292
293static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
294 int *qerr)
295{
296 struct drr_sched *q = qdisc_priv(sch);
297 struct drr_class *cl;
298 struct tcf_result res;
299 struct tcf_proto *fl;
300 int result;
301
302 if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
303 cl = drr_find_class(sch, skb->priority);
304 if (cl != NULL)
305 return cl;
306 }
307
308 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
309 fl = rcu_dereference_bh(q->filter_list);
310 result = tcf_classify(skb, NULL, fl, &res, false);
311 if (result >= 0) {
312#ifdef CONFIG_NET_CLS_ACT
313 switch (result) {
314 case TC_ACT_QUEUED:
315 case TC_ACT_STOLEN:
316 case TC_ACT_TRAP:
317 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
318 fallthrough;
319 case TC_ACT_SHOT:
320 return NULL;
321 }
322#endif
323 cl = (struct drr_class *)res.class;
324 if (cl == NULL)
325 cl = drr_find_class(sch, res.classid);
326 return cl;
327 }
328 return NULL;
329}
330
331static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch,
332 struct sk_buff **to_free)
333{
334 unsigned int len = qdisc_pkt_len(skb);
335 struct drr_sched *q = qdisc_priv(sch);
336 struct drr_class *cl;
337 int err = 0;
338 bool first;
339
340 cl = drr_classify(skb, sch, &err);
341 if (cl == NULL) {
342 if (err & __NET_XMIT_BYPASS)
343 qdisc_qstats_drop(sch);
344 __qdisc_drop(skb, to_free);
345 return err;
346 }
347
348 first = !cl->qdisc->q.qlen;
349 err = qdisc_enqueue(skb, cl->qdisc, to_free);
350 if (unlikely(err != NET_XMIT_SUCCESS)) {
351 if (net_xmit_drop_count(err)) {
352 cl->qstats.drops++;
353 qdisc_qstats_drop(sch);
354 }
355 return err;
356 }
357
358 if (first) {
359 list_add_tail(&cl->alist, &q->active);
360 cl->deficit = cl->quantum;
361 }
362
363 sch->qstats.backlog += len;
364 sch->q.qlen++;
365 return err;
366}
367
368static struct sk_buff *drr_dequeue(struct Qdisc *sch)
369{
370 struct drr_sched *q = qdisc_priv(sch);
371 struct drr_class *cl;
372 struct sk_buff *skb;
373 unsigned int len;
374
375 if (list_empty(&q->active))
376 goto out;
377 while (1) {
378 cl = list_first_entry(&q->active, struct drr_class, alist);
379 skb = cl->qdisc->ops->peek(cl->qdisc);
380 if (skb == NULL) {
381 qdisc_warn_nonwc(__func__, cl->qdisc);
382 goto out;
383 }
384
385 len = qdisc_pkt_len(skb);
386 if (len <= cl->deficit) {
387 cl->deficit -= len;
388 skb = qdisc_dequeue_peeked(cl->qdisc);
389 if (unlikely(skb == NULL))
390 goto out;
391 if (cl->qdisc->q.qlen == 0)
392 list_del(&cl->alist);
393
394 bstats_update(&cl->bstats, skb);
395 qdisc_bstats_update(sch, skb);
396 qdisc_qstats_backlog_dec(sch, skb);
397 sch->q.qlen--;
398 return skb;
399 }
400
401 cl->deficit += cl->quantum;
402 list_move_tail(&cl->alist, &q->active);
403 }
404out:
405 return NULL;
406}
407
408static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt,
409 struct netlink_ext_ack *extack)
410{
411 struct drr_sched *q = qdisc_priv(sch);
412 int err;
413
414 err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
415 if (err)
416 return err;
417 err = qdisc_class_hash_init(&q->clhash);
418 if (err < 0)
419 return err;
420 INIT_LIST_HEAD(&q->active);
421 return 0;
422}
423
424static void drr_reset_qdisc(struct Qdisc *sch)
425{
426 struct drr_sched *q = qdisc_priv(sch);
427 struct drr_class *cl;
428 unsigned int i;
429
430 for (i = 0; i < q->clhash.hashsize; i++) {
431 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
432 if (cl->qdisc->q.qlen)
433 list_del(&cl->alist);
434 qdisc_reset(cl->qdisc);
435 }
436 }
437}
438
439static void drr_destroy_qdisc(struct Qdisc *sch)
440{
441 struct drr_sched *q = qdisc_priv(sch);
442 struct drr_class *cl;
443 struct hlist_node *next;
444 unsigned int i;
445
446 tcf_block_put(q->block);
447
448 for (i = 0; i < q->clhash.hashsize; i++) {
449 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
450 common.hnode)
451 drr_destroy_class(sch, cl);
452 }
453 qdisc_class_hash_destroy(&q->clhash);
454}
455
456static const struct Qdisc_class_ops drr_class_ops = {
457 .change = drr_change_class,
458 .delete = drr_delete_class,
459 .find = drr_search_class,
460 .tcf_block = drr_tcf_block,
461 .bind_tcf = drr_bind_tcf,
462 .unbind_tcf = drr_unbind_tcf,
463 .graft = drr_graft_class,
464 .leaf = drr_class_leaf,
465 .qlen_notify = drr_qlen_notify,
466 .dump = drr_dump_class,
467 .dump_stats = drr_dump_class_stats,
468 .walk = drr_walk,
469};
470
471static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
472 .cl_ops = &drr_class_ops,
473 .id = "drr",
474 .priv_size = sizeof(struct drr_sched),
475 .enqueue = drr_enqueue,
476 .dequeue = drr_dequeue,
477 .peek = qdisc_peek_dequeued,
478 .init = drr_init_qdisc,
479 .reset = drr_reset_qdisc,
480 .destroy = drr_destroy_qdisc,
481 .owner = THIS_MODULE,
482};
483
484static int __init drr_init(void)
485{
486 return register_qdisc(&drr_qdisc_ops);
487}
488
489static void __exit drr_exit(void)
490{
491 unregister_qdisc(&drr_qdisc_ops);
492}
493
494module_init(drr_init);
495module_exit(drr_exit);
496MODULE_LICENSE("GPL");