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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/*
2 * net/sched/sch_drr.c Deficit Round Robin scheduler
3 *
4 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * version 2 as published by the Free Software Foundation.
9 */
10
11#include <linux/module.h>
12#include <linux/slab.h>
13#include <linux/init.h>
14#include <linux/errno.h>
15#include <linux/netdevice.h>
16#include <linux/pkt_sched.h>
17#include <net/sch_generic.h>
18#include <net/pkt_sched.h>
19#include <net/pkt_cls.h>
20
21struct drr_class {
22 struct Qdisc_class_common common;
23 unsigned int refcnt;
24 unsigned int filter_cnt;
25
26 struct gnet_stats_basic_packed bstats;
27 struct gnet_stats_queue qstats;
28 struct gnet_stats_rate_est64 rate_est;
29 struct list_head alist;
30 struct Qdisc *qdisc;
31
32 u32 quantum;
33 u32 deficit;
34};
35
36struct drr_sched {
37 struct list_head active;
38 struct tcf_proto *filter_list;
39 struct Qdisc_class_hash clhash;
40};
41
42static struct drr_class *drr_find_class(struct Qdisc *sch, u32 classid)
43{
44 struct drr_sched *q = qdisc_priv(sch);
45 struct Qdisc_class_common *clc;
46
47 clc = qdisc_class_find(&q->clhash, classid);
48 if (clc == NULL)
49 return NULL;
50 return container_of(clc, struct drr_class, common);
51}
52
53static void drr_purge_queue(struct drr_class *cl)
54{
55 unsigned int len = cl->qdisc->q.qlen;
56
57 qdisc_reset(cl->qdisc);
58 qdisc_tree_decrease_qlen(cl->qdisc, len);
59}
60
61static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
62 [TCA_DRR_QUANTUM] = { .type = NLA_U32 },
63};
64
65static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
66 struct nlattr **tca, unsigned long *arg)
67{
68 struct drr_sched *q = qdisc_priv(sch);
69 struct drr_class *cl = (struct drr_class *)*arg;
70 struct nlattr *opt = tca[TCA_OPTIONS];
71 struct nlattr *tb[TCA_DRR_MAX + 1];
72 u32 quantum;
73 int err;
74
75 if (!opt)
76 return -EINVAL;
77
78 err = nla_parse_nested(tb, TCA_DRR_MAX, opt, drr_policy);
79 if (err < 0)
80 return err;
81
82 if (tb[TCA_DRR_QUANTUM]) {
83 quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
84 if (quantum == 0)
85 return -EINVAL;
86 } else
87 quantum = psched_mtu(qdisc_dev(sch));
88
89 if (cl != NULL) {
90 if (tca[TCA_RATE]) {
91 err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
92 qdisc_root_sleeping_lock(sch),
93 tca[TCA_RATE]);
94 if (err)
95 return err;
96 }
97
98 sch_tree_lock(sch);
99 if (tb[TCA_DRR_QUANTUM])
100 cl->quantum = quantum;
101 sch_tree_unlock(sch);
102
103 return 0;
104 }
105
106 cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
107 if (cl == NULL)
108 return -ENOBUFS;
109
110 cl->refcnt = 1;
111 cl->common.classid = classid;
112 cl->quantum = quantum;
113 cl->qdisc = qdisc_create_dflt(sch->dev_queue,
114 &pfifo_qdisc_ops, classid);
115 if (cl->qdisc == NULL)
116 cl->qdisc = &noop_qdisc;
117
118 if (tca[TCA_RATE]) {
119 err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
120 qdisc_root_sleeping_lock(sch),
121 tca[TCA_RATE]);
122 if (err) {
123 qdisc_destroy(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->bstats, &cl->rate_est);
142 qdisc_destroy(cl->qdisc);
143 kfree(cl);
144}
145
146static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
147{
148 struct drr_sched *q = qdisc_priv(sch);
149 struct drr_class *cl = (struct drr_class *)arg;
150
151 if (cl->filter_cnt > 0)
152 return -EBUSY;
153
154 sch_tree_lock(sch);
155
156 drr_purge_queue(cl);
157 qdisc_class_hash_remove(&q->clhash, &cl->common);
158
159 BUG_ON(--cl->refcnt == 0);
160 /*
161 * This shouldn't happen: we "hold" one cops->get() when called
162 * from tc_ctl_tclass; the destroy method is done from cops->put().
163 */
164
165 sch_tree_unlock(sch);
166 return 0;
167}
168
169static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
170{
171 struct drr_class *cl = drr_find_class(sch, classid);
172
173 if (cl != NULL)
174 cl->refcnt++;
175
176 return (unsigned long)cl;
177}
178
179static void drr_put_class(struct Qdisc *sch, unsigned long arg)
180{
181 struct drr_class *cl = (struct drr_class *)arg;
182
183 if (--cl->refcnt == 0)
184 drr_destroy_class(sch, cl);
185}
186
187static struct tcf_proto **drr_tcf_chain(struct Qdisc *sch, unsigned long cl)
188{
189 struct drr_sched *q = qdisc_priv(sch);
190
191 if (cl)
192 return NULL;
193
194 return &q->filter_list;
195}
196
197static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
198 u32 classid)
199{
200 struct drr_class *cl = drr_find_class(sch, classid);
201
202 if (cl != NULL)
203 cl->filter_cnt++;
204
205 return (unsigned long)cl;
206}
207
208static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
209{
210 struct drr_class *cl = (struct drr_class *)arg;
211
212 cl->filter_cnt--;
213}
214
215static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
216 struct Qdisc *new, struct Qdisc **old)
217{
218 struct drr_class *cl = (struct drr_class *)arg;
219
220 if (new == NULL) {
221 new = qdisc_create_dflt(sch->dev_queue,
222 &pfifo_qdisc_ops, cl->common.classid);
223 if (new == NULL)
224 new = &noop_qdisc;
225 }
226
227 sch_tree_lock(sch);
228 drr_purge_queue(cl);
229 *old = cl->qdisc;
230 cl->qdisc = new;
231 sch_tree_unlock(sch);
232 return 0;
233}
234
235static struct Qdisc *drr_class_leaf(struct Qdisc *sch, unsigned long arg)
236{
237 struct drr_class *cl = (struct drr_class *)arg;
238
239 return cl->qdisc;
240}
241
242static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
243{
244 struct drr_class *cl = (struct drr_class *)arg;
245
246 if (cl->qdisc->q.qlen == 0)
247 list_del(&cl->alist);
248}
249
250static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
251 struct sk_buff *skb, struct tcmsg *tcm)
252{
253 struct drr_class *cl = (struct drr_class *)arg;
254 struct nlattr *nest;
255
256 tcm->tcm_parent = TC_H_ROOT;
257 tcm->tcm_handle = cl->common.classid;
258 tcm->tcm_info = cl->qdisc->handle;
259
260 nest = nla_nest_start(skb, TCA_OPTIONS);
261 if (nest == NULL)
262 goto nla_put_failure;
263 if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
264 goto nla_put_failure;
265 return nla_nest_end(skb, nest);
266
267nla_put_failure:
268 nla_nest_cancel(skb, nest);
269 return -EMSGSIZE;
270}
271
272static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
273 struct gnet_dump *d)
274{
275 struct drr_class *cl = (struct drr_class *)arg;
276 struct tc_drr_stats xstats;
277
278 memset(&xstats, 0, sizeof(xstats));
279 if (cl->qdisc->q.qlen) {
280 xstats.deficit = cl->deficit;
281 cl->qdisc->qstats.qlen = cl->qdisc->q.qlen;
282 }
283
284 if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
285 gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
286 gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
287 return -1;
288
289 return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
290}
291
292static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg)
293{
294 struct drr_sched *q = qdisc_priv(sch);
295 struct drr_class *cl;
296 unsigned int i;
297
298 if (arg->stop)
299 return;
300
301 for (i = 0; i < q->clhash.hashsize; i++) {
302 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
303 if (arg->count < arg->skip) {
304 arg->count++;
305 continue;
306 }
307 if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
308 arg->stop = 1;
309 return;
310 }
311 arg->count++;
312 }
313 }
314}
315
316static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
317 int *qerr)
318{
319 struct drr_sched *q = qdisc_priv(sch);
320 struct drr_class *cl;
321 struct tcf_result res;
322 int result;
323
324 if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
325 cl = drr_find_class(sch, skb->priority);
326 if (cl != NULL)
327 return cl;
328 }
329
330 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
331 result = tc_classify(skb, q->filter_list, &res);
332 if (result >= 0) {
333#ifdef CONFIG_NET_CLS_ACT
334 switch (result) {
335 case TC_ACT_QUEUED:
336 case TC_ACT_STOLEN:
337 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
338 case TC_ACT_SHOT:
339 return NULL;
340 }
341#endif
342 cl = (struct drr_class *)res.class;
343 if (cl == NULL)
344 cl = drr_find_class(sch, res.classid);
345 return cl;
346 }
347 return NULL;
348}
349
350static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch)
351{
352 struct drr_sched *q = qdisc_priv(sch);
353 struct drr_class *cl;
354 int err = 0;
355
356 cl = drr_classify(skb, sch, &err);
357 if (cl == NULL) {
358 if (err & __NET_XMIT_BYPASS)
359 sch->qstats.drops++;
360 kfree_skb(skb);
361 return err;
362 }
363
364 err = qdisc_enqueue(skb, cl->qdisc);
365 if (unlikely(err != NET_XMIT_SUCCESS)) {
366 if (net_xmit_drop_count(err)) {
367 cl->qstats.drops++;
368 sch->qstats.drops++;
369 }
370 return err;
371 }
372
373 if (cl->qdisc->q.qlen == 1) {
374 list_add_tail(&cl->alist, &q->active);
375 cl->deficit = cl->quantum;
376 }
377
378 sch->q.qlen++;
379 return err;
380}
381
382static struct sk_buff *drr_dequeue(struct Qdisc *sch)
383{
384 struct drr_sched *q = qdisc_priv(sch);
385 struct drr_class *cl;
386 struct sk_buff *skb;
387 unsigned int len;
388
389 if (list_empty(&q->active))
390 goto out;
391 while (1) {
392 cl = list_first_entry(&q->active, struct drr_class, alist);
393 skb = cl->qdisc->ops->peek(cl->qdisc);
394 if (skb == NULL)
395 goto out;
396
397 len = qdisc_pkt_len(skb);
398 if (len <= cl->deficit) {
399 cl->deficit -= len;
400 skb = qdisc_dequeue_peeked(cl->qdisc);
401 if (cl->qdisc->q.qlen == 0)
402 list_del(&cl->alist);
403
404 bstats_update(&cl->bstats, skb);
405 qdisc_bstats_update(sch, skb);
406 sch->q.qlen--;
407 return skb;
408 }
409
410 cl->deficit += cl->quantum;
411 list_move_tail(&cl->alist, &q->active);
412 }
413out:
414 return NULL;
415}
416
417static unsigned int drr_drop(struct Qdisc *sch)
418{
419 struct drr_sched *q = qdisc_priv(sch);
420 struct drr_class *cl;
421 unsigned int len;
422
423 list_for_each_entry(cl, &q->active, alist) {
424 if (cl->qdisc->ops->drop) {
425 len = cl->qdisc->ops->drop(cl->qdisc);
426 if (len > 0) {
427 sch->q.qlen--;
428 if (cl->qdisc->q.qlen == 0)
429 list_del(&cl->alist);
430 return len;
431 }
432 }
433 }
434 return 0;
435}
436
437static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
438{
439 struct drr_sched *q = qdisc_priv(sch);
440 int err;
441
442 err = qdisc_class_hash_init(&q->clhash);
443 if (err < 0)
444 return err;
445 INIT_LIST_HEAD(&q->active);
446 return 0;
447}
448
449static void drr_reset_qdisc(struct Qdisc *sch)
450{
451 struct drr_sched *q = qdisc_priv(sch);
452 struct drr_class *cl;
453 unsigned int i;
454
455 for (i = 0; i < q->clhash.hashsize; i++) {
456 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
457 if (cl->qdisc->q.qlen)
458 list_del(&cl->alist);
459 qdisc_reset(cl->qdisc);
460 }
461 }
462 sch->q.qlen = 0;
463}
464
465static void drr_destroy_qdisc(struct Qdisc *sch)
466{
467 struct drr_sched *q = qdisc_priv(sch);
468 struct drr_class *cl;
469 struct hlist_node *next;
470 unsigned int i;
471
472 tcf_destroy_chain(&q->filter_list);
473
474 for (i = 0; i < q->clhash.hashsize; i++) {
475 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
476 common.hnode)
477 drr_destroy_class(sch, cl);
478 }
479 qdisc_class_hash_destroy(&q->clhash);
480}
481
482static const struct Qdisc_class_ops drr_class_ops = {
483 .change = drr_change_class,
484 .delete = drr_delete_class,
485 .get = drr_get_class,
486 .put = drr_put_class,
487 .tcf_chain = drr_tcf_chain,
488 .bind_tcf = drr_bind_tcf,
489 .unbind_tcf = drr_unbind_tcf,
490 .graft = drr_graft_class,
491 .leaf = drr_class_leaf,
492 .qlen_notify = drr_qlen_notify,
493 .dump = drr_dump_class,
494 .dump_stats = drr_dump_class_stats,
495 .walk = drr_walk,
496};
497
498static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
499 .cl_ops = &drr_class_ops,
500 .id = "drr",
501 .priv_size = sizeof(struct drr_sched),
502 .enqueue = drr_enqueue,
503 .dequeue = drr_dequeue,
504 .peek = qdisc_peek_dequeued,
505 .drop = drr_drop,
506 .init = drr_init_qdisc,
507 .reset = drr_reset_qdisc,
508 .destroy = drr_destroy_qdisc,
509 .owner = THIS_MODULE,
510};
511
512static int __init drr_init(void)
513{
514 return register_qdisc(&drr_qdisc_ops);
515}
516
517static void __exit drr_exit(void)
518{
519 unregister_qdisc(&drr_qdisc_ops);
520}
521
522module_init(drr_init);
523module_exit(drr_exit);
524MODULE_LICENSE("GPL");