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19#include <linux/module.h>
20#include <linux/slab.h>
21#include <linux/types.h>
22#include <linux/kernel.h>
23#include <linux/string.h>
24#include <linux/errno.h>
25#include <linux/skbuff.h>
26#include <net/netlink.h>
27#include <net/pkt_sched.h>
28
29
30struct multiq_sched_data {
31 u16 bands;
32 u16 max_bands;
33 u16 curband;
34 struct tcf_proto __rcu *filter_list;
35 struct Qdisc **queues;
36};
37
38
39static struct Qdisc *
40multiq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
41{
42 struct multiq_sched_data *q = qdisc_priv(sch);
43 u32 band;
44 struct tcf_result res;
45 struct tcf_proto *fl = rcu_dereference_bh(q->filter_list);
46 int err;
47
48 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
49 err = tc_classify(skb, fl, &res, false);
50#ifdef CONFIG_NET_CLS_ACT
51 switch (err) {
52 case TC_ACT_STOLEN:
53 case TC_ACT_QUEUED:
54 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
55 case TC_ACT_SHOT:
56 return NULL;
57 }
58#endif
59 band = skb_get_queue_mapping(skb);
60
61 if (band >= q->bands)
62 return q->queues[0];
63
64 return q->queues[band];
65}
66
67static int
68multiq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
69 struct sk_buff **to_free)
70{
71 struct Qdisc *qdisc;
72 int ret;
73
74 qdisc = multiq_classify(skb, sch, &ret);
75#ifdef CONFIG_NET_CLS_ACT
76 if (qdisc == NULL) {
77
78 if (ret & __NET_XMIT_BYPASS)
79 qdisc_qstats_drop(sch);
80 __qdisc_drop(skb, to_free);
81 return ret;
82 }
83#endif
84
85 ret = qdisc_enqueue(skb, qdisc, to_free);
86 if (ret == NET_XMIT_SUCCESS) {
87 sch->q.qlen++;
88 return NET_XMIT_SUCCESS;
89 }
90 if (net_xmit_drop_count(ret))
91 qdisc_qstats_drop(sch);
92 return ret;
93}
94
95static struct sk_buff *multiq_dequeue(struct Qdisc *sch)
96{
97 struct multiq_sched_data *q = qdisc_priv(sch);
98 struct Qdisc *qdisc;
99 struct sk_buff *skb;
100 int band;
101
102 for (band = 0; band < q->bands; band++) {
103
104 q->curband++;
105 if (q->curband >= q->bands)
106 q->curband = 0;
107
108
109
110
111 if (!netif_xmit_stopped(
112 netdev_get_tx_queue(qdisc_dev(sch), q->curband))) {
113 qdisc = q->queues[q->curband];
114 skb = qdisc->dequeue(qdisc);
115 if (skb) {
116 qdisc_bstats_update(sch, skb);
117 sch->q.qlen--;
118 return skb;
119 }
120 }
121 }
122 return NULL;
123
124}
125
126static struct sk_buff *multiq_peek(struct Qdisc *sch)
127{
128 struct multiq_sched_data *q = qdisc_priv(sch);
129 unsigned int curband = q->curband;
130 struct Qdisc *qdisc;
131 struct sk_buff *skb;
132 int band;
133
134 for (band = 0; band < q->bands; band++) {
135
136 curband++;
137 if (curband >= q->bands)
138 curband = 0;
139
140
141
142
143 if (!netif_xmit_stopped(
144 netdev_get_tx_queue(qdisc_dev(sch), curband))) {
145 qdisc = q->queues[curband];
146 skb = qdisc->ops->peek(qdisc);
147 if (skb)
148 return skb;
149 }
150 }
151 return NULL;
152
153}
154
155static void
156multiq_reset(struct Qdisc *sch)
157{
158 u16 band;
159 struct multiq_sched_data *q = qdisc_priv(sch);
160
161 for (band = 0; band < q->bands; band++)
162 qdisc_reset(q->queues[band]);
163 sch->q.qlen = 0;
164 q->curband = 0;
165}
166
167static void
168multiq_destroy(struct Qdisc *sch)
169{
170 int band;
171 struct multiq_sched_data *q = qdisc_priv(sch);
172
173 tcf_destroy_chain(&q->filter_list);
174 for (band = 0; band < q->bands; band++)
175 qdisc_destroy(q->queues[band]);
176
177 kfree(q->queues);
178}
179
180static int multiq_tune(struct Qdisc *sch, struct nlattr *opt)
181{
182 struct multiq_sched_data *q = qdisc_priv(sch);
183 struct tc_multiq_qopt *qopt;
184 int i;
185
186 if (!netif_is_multiqueue(qdisc_dev(sch)))
187 return -EOPNOTSUPP;
188 if (nla_len(opt) < sizeof(*qopt))
189 return -EINVAL;
190
191 qopt = nla_data(opt);
192
193 qopt->bands = qdisc_dev(sch)->real_num_tx_queues;
194
195 sch_tree_lock(sch);
196 q->bands = qopt->bands;
197 for (i = q->bands; i < q->max_bands; i++) {
198 if (q->queues[i] != &noop_qdisc) {
199 struct Qdisc *child = q->queues[i];
200 q->queues[i] = &noop_qdisc;
201 qdisc_tree_reduce_backlog(child, child->q.qlen,
202 child->qstats.backlog);
203 qdisc_destroy(child);
204 }
205 }
206
207 sch_tree_unlock(sch);
208
209 for (i = 0; i < q->bands; i++) {
210 if (q->queues[i] == &noop_qdisc) {
211 struct Qdisc *child, *old;
212 child = qdisc_create_dflt(sch->dev_queue,
213 &pfifo_qdisc_ops,
214 TC_H_MAKE(sch->handle,
215 i + 1));
216 if (child) {
217 sch_tree_lock(sch);
218 old = q->queues[i];
219 q->queues[i] = child;
220
221 if (old != &noop_qdisc) {
222 qdisc_tree_reduce_backlog(old,
223 old->q.qlen,
224 old->qstats.backlog);
225 qdisc_destroy(old);
226 }
227 sch_tree_unlock(sch);
228 }
229 }
230 }
231 return 0;
232}
233
234static int multiq_init(struct Qdisc *sch, struct nlattr *opt)
235{
236 struct multiq_sched_data *q = qdisc_priv(sch);
237 int i, err;
238
239 q->queues = NULL;
240
241 if (opt == NULL)
242 return -EINVAL;
243
244 q->max_bands = qdisc_dev(sch)->num_tx_queues;
245
246 q->queues = kcalloc(q->max_bands, sizeof(struct Qdisc *), GFP_KERNEL);
247 if (!q->queues)
248 return -ENOBUFS;
249 for (i = 0; i < q->max_bands; i++)
250 q->queues[i] = &noop_qdisc;
251
252 err = multiq_tune(sch, opt);
253
254 if (err)
255 kfree(q->queues);
256
257 return err;
258}
259
260static int multiq_dump(struct Qdisc *sch, struct sk_buff *skb)
261{
262 struct multiq_sched_data *q = qdisc_priv(sch);
263 unsigned char *b = skb_tail_pointer(skb);
264 struct tc_multiq_qopt opt;
265
266 opt.bands = q->bands;
267 opt.max_bands = q->max_bands;
268
269 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
270 goto nla_put_failure;
271
272 return skb->len;
273
274nla_put_failure:
275 nlmsg_trim(skb, b);
276 return -1;
277}
278
279static int multiq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
280 struct Qdisc **old)
281{
282 struct multiq_sched_data *q = qdisc_priv(sch);
283 unsigned long band = arg - 1;
284
285 if (new == NULL)
286 new = &noop_qdisc;
287
288 *old = qdisc_replace(sch, new, &q->queues[band]);
289 return 0;
290}
291
292static struct Qdisc *
293multiq_leaf(struct Qdisc *sch, unsigned long arg)
294{
295 struct multiq_sched_data *q = qdisc_priv(sch);
296 unsigned long band = arg - 1;
297
298 return q->queues[band];
299}
300
301static unsigned long multiq_get(struct Qdisc *sch, u32 classid)
302{
303 struct multiq_sched_data *q = qdisc_priv(sch);
304 unsigned long band = TC_H_MIN(classid);
305
306 if (band - 1 >= q->bands)
307 return 0;
308 return band;
309}
310
311static unsigned long multiq_bind(struct Qdisc *sch, unsigned long parent,
312 u32 classid)
313{
314 return multiq_get(sch, classid);
315}
316
317
318static void multiq_put(struct Qdisc *q, unsigned long cl)
319{
320}
321
322static int multiq_dump_class(struct Qdisc *sch, unsigned long cl,
323 struct sk_buff *skb, struct tcmsg *tcm)
324{
325 struct multiq_sched_data *q = qdisc_priv(sch);
326
327 tcm->tcm_handle |= TC_H_MIN(cl);
328 tcm->tcm_info = q->queues[cl - 1]->handle;
329 return 0;
330}
331
332static int multiq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
333 struct gnet_dump *d)
334{
335 struct multiq_sched_data *q = qdisc_priv(sch);
336 struct Qdisc *cl_q;
337
338 cl_q = q->queues[cl - 1];
339 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
340 d, NULL, &cl_q->bstats) < 0 ||
341 gnet_stats_copy_queue(d, NULL, &cl_q->qstats, cl_q->q.qlen) < 0)
342 return -1;
343
344 return 0;
345}
346
347static void multiq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
348{
349 struct multiq_sched_data *q = qdisc_priv(sch);
350 int band;
351
352 if (arg->stop)
353 return;
354
355 for (band = 0; band < q->bands; band++) {
356 if (arg->count < arg->skip) {
357 arg->count++;
358 continue;
359 }
360 if (arg->fn(sch, band + 1, arg) < 0) {
361 arg->stop = 1;
362 break;
363 }
364 arg->count++;
365 }
366}
367
368static struct tcf_proto __rcu **multiq_find_tcf(struct Qdisc *sch,
369 unsigned long cl)
370{
371 struct multiq_sched_data *q = qdisc_priv(sch);
372
373 if (cl)
374 return NULL;
375 return &q->filter_list;
376}
377
378static const struct Qdisc_class_ops multiq_class_ops = {
379 .graft = multiq_graft,
380 .leaf = multiq_leaf,
381 .get = multiq_get,
382 .put = multiq_put,
383 .walk = multiq_walk,
384 .tcf_chain = multiq_find_tcf,
385 .bind_tcf = multiq_bind,
386 .unbind_tcf = multiq_put,
387 .dump = multiq_dump_class,
388 .dump_stats = multiq_dump_class_stats,
389};
390
391static struct Qdisc_ops multiq_qdisc_ops __read_mostly = {
392 .next = NULL,
393 .cl_ops = &multiq_class_ops,
394 .id = "multiq",
395 .priv_size = sizeof(struct multiq_sched_data),
396 .enqueue = multiq_enqueue,
397 .dequeue = multiq_dequeue,
398 .peek = multiq_peek,
399 .init = multiq_init,
400 .reset = multiq_reset,
401 .destroy = multiq_destroy,
402 .change = multiq_tune,
403 .dump = multiq_dump,
404 .owner = THIS_MODULE,
405};
406
407static int __init multiq_module_init(void)
408{
409 return register_qdisc(&multiq_qdisc_ops);
410}
411
412static void __exit multiq_module_exit(void)
413{
414 unregister_qdisc(&multiq_qdisc_ops);
415}
416
417module_init(multiq_module_init)
418module_exit(multiq_module_exit)
419
420MODULE_LICENSE("GPL");
421
