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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 __rcu *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, NULL,
92 &cl->rate_est,
93 qdisc_root_sleeping_lock(sch),
94 tca[TCA_RATE]);
95 if (err)
96 return err;
97 }
98
99 sch_tree_lock(sch);
100 if (tb[TCA_DRR_QUANTUM])
101 cl->quantum = quantum;
102 sch_tree_unlock(sch);
103
104 return 0;
105 }
106
107 cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
108 if (cl == NULL)
109 return -ENOBUFS;
110
111 cl->refcnt = 1;
112 cl->common.classid = classid;
113 cl->quantum = quantum;
114 cl->qdisc = qdisc_create_dflt(sch->dev_queue,
115 &pfifo_qdisc_ops, classid);
116 if (cl->qdisc == NULL)
117 cl->qdisc = &noop_qdisc;
118
119 if (tca[TCA_RATE]) {
120 err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est,
121 qdisc_root_sleeping_lock(sch),
122 tca[TCA_RATE]);
123 if (err) {
124 qdisc_destroy(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->bstats, &cl->rate_est);
143 qdisc_destroy(cl->qdisc);
144 kfree(cl);
145}
146
147static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
148{
149 struct drr_sched *q = qdisc_priv(sch);
150 struct drr_class *cl = (struct drr_class *)arg;
151
152 if (cl->filter_cnt > 0)
153 return -EBUSY;
154
155 sch_tree_lock(sch);
156
157 drr_purge_queue(cl);
158 qdisc_class_hash_remove(&q->clhash, &cl->common);
159
160 BUG_ON(--cl->refcnt == 0);
161
162
163
164
165
166 sch_tree_unlock(sch);
167 return 0;
168}
169
170static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
171{
172 struct drr_class *cl = drr_find_class(sch, classid);
173
174 if (cl != NULL)
175 cl->refcnt++;
176
177 return (unsigned long)cl;
178}
179
180static void drr_put_class(struct Qdisc *sch, unsigned long arg)
181{
182 struct drr_class *cl = (struct drr_class *)arg;
183
184 if (--cl->refcnt == 0)
185 drr_destroy_class(sch, cl);
186}
187
188static struct tcf_proto __rcu **drr_tcf_chain(struct Qdisc *sch,
189 unsigned long cl)
190{
191 struct drr_sched *q = qdisc_priv(sch);
192
193 if (cl)
194 return NULL;
195
196 return &q->filter_list;
197}
198
199static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
200 u32 classid)
201{
202 struct drr_class *cl = drr_find_class(sch, classid);
203
204 if (cl != NULL)
205 cl->filter_cnt++;
206
207 return (unsigned long)cl;
208}
209
210static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
211{
212 struct drr_class *cl = (struct drr_class *)arg;
213
214 cl->filter_cnt--;
215}
216
217static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
218 struct Qdisc *new, struct Qdisc **old)
219{
220 struct drr_class *cl = (struct drr_class *)arg;
221
222 if (new == NULL) {
223 new = qdisc_create_dflt(sch->dev_queue,
224 &pfifo_qdisc_ops, cl->common.classid);
225 if (new == NULL)
226 new = &noop_qdisc;
227 }
228
229 sch_tree_lock(sch);
230 drr_purge_queue(cl);
231 *old = cl->qdisc;
232 cl->qdisc = new;
233 sch_tree_unlock(sch);
234 return 0;
235}
236
237static struct Qdisc *drr_class_leaf(struct Qdisc *sch, unsigned long arg)
238{
239 struct drr_class *cl = (struct drr_class *)arg;
240
241 return cl->qdisc;
242}
243
244static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
245{
246 struct drr_class *cl = (struct drr_class *)arg;
247
248 if (cl->qdisc->q.qlen == 0)
249 list_del(&cl->alist);
250}
251
252static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
253 struct sk_buff *skb, struct tcmsg *tcm)
254{
255 struct drr_class *cl = (struct drr_class *)arg;
256 struct nlattr *nest;
257
258 tcm->tcm_parent = TC_H_ROOT;
259 tcm->tcm_handle = cl->common.classid;
260 tcm->tcm_info = cl->qdisc->handle;
261
262 nest = nla_nest_start(skb, TCA_OPTIONS);
263 if (nest == NULL)
264 goto nla_put_failure;
265 if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
266 goto nla_put_failure;
267 return nla_nest_end(skb, nest);
268
269nla_put_failure:
270 nla_nest_cancel(skb, nest);
271 return -EMSGSIZE;
272}
273
274static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
275 struct gnet_dump *d)
276{
277 struct drr_class *cl = (struct drr_class *)arg;
278 __u32 qlen = cl->qdisc->q.qlen;
279 struct tc_drr_stats xstats;
280
281 memset(&xstats, 0, sizeof(xstats));
282 if (qlen)
283 xstats.deficit = cl->deficit;
284
285 if (gnet_stats_copy_basic(d, NULL, &cl->bstats) < 0 ||
286 gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
287 gnet_stats_copy_queue(d, NULL, &cl->qdisc->qstats, qlen) < 0)
288 return -1;
289
290 return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
291}
292
293static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg)
294{
295 struct drr_sched *q = qdisc_priv(sch);
296 struct drr_class *cl;
297 unsigned int i;
298
299 if (arg->stop)
300 return;
301
302 for (i = 0; i < q->clhash.hashsize; i++) {
303 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
304 if (arg->count < arg->skip) {
305 arg->count++;
306 continue;
307 }
308 if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
309 arg->stop = 1;
310 return;
311 }
312 arg->count++;
313 }
314 }
315}
316
317static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
318 int *qerr)
319{
320 struct drr_sched *q = qdisc_priv(sch);
321 struct drr_class *cl;
322 struct tcf_result res;
323 struct tcf_proto *fl;
324 int result;
325
326 if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
327 cl = drr_find_class(sch, skb->priority);
328 if (cl != NULL)
329 return cl;
330 }
331
332 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
333 fl = rcu_dereference_bh(q->filter_list);
334 result = tc_classify(skb, fl, &res, false);
335 if (result >= 0) {
336#ifdef CONFIG_NET_CLS_ACT
337 switch (result) {
338 case TC_ACT_QUEUED:
339 case TC_ACT_STOLEN:
340 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
341 case TC_ACT_SHOT:
342 return NULL;
343 }
344#endif
345 cl = (struct drr_class *)res.class;
346 if (cl == NULL)
347 cl = drr_find_class(sch, res.classid);
348 return cl;
349 }
350 return NULL;
351}
352
353static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch)
354{
355 struct drr_sched *q = qdisc_priv(sch);
356 struct drr_class *cl;
357 int err = 0;
358
359 cl = drr_classify(skb, sch, &err);
360 if (cl == NULL) {
361 if (err & __NET_XMIT_BYPASS)
362 qdisc_qstats_drop(sch);
363 kfree_skb(skb);
364 return err;
365 }
366
367 err = qdisc_enqueue(skb, cl->qdisc);
368 if (unlikely(err != NET_XMIT_SUCCESS)) {
369 if (net_xmit_drop_count(err)) {
370 cl->qstats.drops++;
371 qdisc_qstats_drop(sch);
372 }
373 return err;
374 }
375
376 if (cl->qdisc->q.qlen == 1) {
377 list_add_tail(&cl->alist, &q->active);
378 cl->deficit = cl->quantum;
379 }
380
381 sch->q.qlen++;
382 return err;
383}
384
385static struct sk_buff *drr_dequeue(struct Qdisc *sch)
386{
387 struct drr_sched *q = qdisc_priv(sch);
388 struct drr_class *cl;
389 struct sk_buff *skb;
390 unsigned int len;
391
392 if (list_empty(&q->active))
393 goto out;
394 while (1) {
395 cl = list_first_entry(&q->active, struct drr_class, alist);
396 skb = cl->qdisc->ops->peek(cl->qdisc);
397 if (skb == NULL) {
398 qdisc_warn_nonwc(__func__, cl->qdisc);
399 goto out;
400 }
401
402 len = qdisc_pkt_len(skb);
403 if (len <= cl->deficit) {
404 cl->deficit -= len;
405 skb = qdisc_dequeue_peeked(cl->qdisc);
406 if (cl->qdisc->q.qlen == 0)
407 list_del(&cl->alist);
408
409 bstats_update(&cl->bstats, skb);
410 qdisc_bstats_update(sch, skb);
411 sch->q.qlen--;
412 return skb;
413 }
414
415 cl->deficit += cl->quantum;
416 list_move_tail(&cl->alist, &q->active);
417 }
418out:
419 return NULL;
420}
421
422static unsigned int drr_drop(struct Qdisc *sch)
423{
424 struct drr_sched *q = qdisc_priv(sch);
425 struct drr_class *cl;
426 unsigned int len;
427
428 list_for_each_entry(cl, &q->active, alist) {
429 if (cl->qdisc->ops->drop) {
430 len = cl->qdisc->ops->drop(cl->qdisc);
431 if (len > 0) {
432 sch->q.qlen--;
433 if (cl->qdisc->q.qlen == 0)
434 list_del(&cl->alist);
435 return len;
436 }
437 }
438 }
439 return 0;
440}
441
442static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
443{
444 struct drr_sched *q = qdisc_priv(sch);
445 int err;
446
447 err = qdisc_class_hash_init(&q->clhash);
448 if (err < 0)
449 return err;
450 INIT_LIST_HEAD(&q->active);
451 return 0;
452}
453
454static void drr_reset_qdisc(struct Qdisc *sch)
455{
456 struct drr_sched *q = qdisc_priv(sch);
457 struct drr_class *cl;
458 unsigned int i;
459
460 for (i = 0; i < q->clhash.hashsize; i++) {
461 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
462 if (cl->qdisc->q.qlen)
463 list_del(&cl->alist);
464 qdisc_reset(cl->qdisc);
465 }
466 }
467 sch->q.qlen = 0;
468}
469
470static void drr_destroy_qdisc(struct Qdisc *sch)
471{
472 struct drr_sched *q = qdisc_priv(sch);
473 struct drr_class *cl;
474 struct hlist_node *next;
475 unsigned int i;
476
477 tcf_destroy_chain(&q->filter_list);
478
479 for (i = 0; i < q->clhash.hashsize; i++) {
480 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
481 common.hnode)
482 drr_destroy_class(sch, cl);
483 }
484 qdisc_class_hash_destroy(&q->clhash);
485}
486
487static const struct Qdisc_class_ops drr_class_ops = {
488 .change = drr_change_class,
489 .delete = drr_delete_class,
490 .get = drr_get_class,
491 .put = drr_put_class,
492 .tcf_chain = drr_tcf_chain,
493 .bind_tcf = drr_bind_tcf,
494 .unbind_tcf = drr_unbind_tcf,
495 .graft = drr_graft_class,
496 .leaf = drr_class_leaf,
497 .qlen_notify = drr_qlen_notify,
498 .dump = drr_dump_class,
499 .dump_stats = drr_dump_class_stats,
500 .walk = drr_walk,
501};
502
503static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
504 .cl_ops = &drr_class_ops,
505 .id = "drr",
506 .priv_size = sizeof(struct drr_sched),
507 .enqueue = drr_enqueue,
508 .dequeue = drr_dequeue,
509 .peek = qdisc_peek_dequeued,
510 .drop = drr_drop,
511 .init = drr_init_qdisc,
512 .reset = drr_reset_qdisc,
513 .destroy = drr_destroy_qdisc,
514 .owner = THIS_MODULE,
515};
516
517static int __init drr_init(void)
518{
519 return register_qdisc(&drr_qdisc_ops);
520}
521
522static void __exit drr_exit(void)
523{
524 unregister_qdisc(&drr_qdisc_ops);
525}
526
527module_init(drr_init);
528module_exit(drr_exit);
529MODULE_LICENSE("GPL");
530
