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10#include <linux/module.h>
11#include <linux/slab.h>
12#include <linux/types.h>
13#include <linux/kernel.h>
14#include <linux/string.h>
15#include <linux/errno.h>
16#include <linux/skbuff.h>
17#include <net/netlink.h>
18#include <net/pkt_sched.h>
19#include <net/pkt_cls.h>
20
21struct prio_sched_data {
22 int bands;
23 struct tcf_proto __rcu *filter_list;
24 struct tcf_block *block;
25 u8 prio2band[TC_PRIO_MAX+1];
26 struct Qdisc *queues[TCQ_PRIO_BANDS];
27};
28
29
30static struct Qdisc *
31prio_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
32{
33 struct prio_sched_data *q = qdisc_priv(sch);
34 u32 band = skb->priority;
35 struct tcf_result res;
36 struct tcf_proto *fl;
37 int err;
38
39 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
40 if (TC_H_MAJ(skb->priority) != sch->handle) {
41 fl = rcu_dereference_bh(q->filter_list);
42 err = tcf_classify(skb, NULL, fl, &res, false);
43#ifdef CONFIG_NET_CLS_ACT
44 switch (err) {
45 case TC_ACT_STOLEN:
46 case TC_ACT_QUEUED:
47 case TC_ACT_TRAP:
48 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
49 fallthrough;
50 case TC_ACT_SHOT:
51 return NULL;
52 }
53#endif
54 if (!fl || err < 0) {
55 if (TC_H_MAJ(band))
56 band = 0;
57 return q->queues[q->prio2band[band & TC_PRIO_MAX]];
58 }
59 band = res.classid;
60 }
61 band = TC_H_MIN(band) - 1;
62 if (band >= q->bands)
63 return q->queues[q->prio2band[0]];
64
65 return q->queues[band];
66}
67
68static int
69prio_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
70{
71 unsigned int len = qdisc_pkt_len(skb);
72 struct Qdisc *qdisc;
73 int ret;
74
75 qdisc = prio_classify(skb, sch, &ret);
76#ifdef CONFIG_NET_CLS_ACT
77 if (qdisc == NULL) {
78
79 if (ret & __NET_XMIT_BYPASS)
80 qdisc_qstats_drop(sch);
81 __qdisc_drop(skb, to_free);
82 return ret;
83 }
84#endif
85
86 ret = qdisc_enqueue(skb, qdisc, to_free);
87 if (ret == NET_XMIT_SUCCESS) {
88 sch->qstats.backlog += len;
89 sch->q.qlen++;
90 return NET_XMIT_SUCCESS;
91 }
92 if (net_xmit_drop_count(ret))
93 qdisc_qstats_drop(sch);
94 return ret;
95}
96
97static struct sk_buff *prio_peek(struct Qdisc *sch)
98{
99 struct prio_sched_data *q = qdisc_priv(sch);
100 int prio;
101
102 for (prio = 0; prio < q->bands; prio++) {
103 struct Qdisc *qdisc = q->queues[prio];
104 struct sk_buff *skb = qdisc->ops->peek(qdisc);
105 if (skb)
106 return skb;
107 }
108 return NULL;
109}
110
111static struct sk_buff *prio_dequeue(struct Qdisc *sch)
112{
113 struct prio_sched_data *q = qdisc_priv(sch);
114 int prio;
115
116 for (prio = 0; prio < q->bands; prio++) {
117 struct Qdisc *qdisc = q->queues[prio];
118 struct sk_buff *skb = qdisc_dequeue_peeked(qdisc);
119 if (skb) {
120 qdisc_bstats_update(sch, skb);
121 qdisc_qstats_backlog_dec(sch, skb);
122 sch->q.qlen--;
123 return skb;
124 }
125 }
126 return NULL;
127
128}
129
130static void
131prio_reset(struct Qdisc *sch)
132{
133 int prio;
134 struct prio_sched_data *q = qdisc_priv(sch);
135
136 for (prio = 0; prio < q->bands; prio++)
137 qdisc_reset(q->queues[prio]);
138 sch->qstats.backlog = 0;
139 sch->q.qlen = 0;
140}
141
142static int prio_offload(struct Qdisc *sch, struct tc_prio_qopt *qopt)
143{
144 struct net_device *dev = qdisc_dev(sch);
145 struct tc_prio_qopt_offload opt = {
146 .handle = sch->handle,
147 .parent = sch->parent,
148 };
149
150 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
151 return -EOPNOTSUPP;
152
153 if (qopt) {
154 opt.command = TC_PRIO_REPLACE;
155 opt.replace_params.bands = qopt->bands;
156 memcpy(&opt.replace_params.priomap, qopt->priomap,
157 TC_PRIO_MAX + 1);
158 opt.replace_params.qstats = &sch->qstats;
159 } else {
160 opt.command = TC_PRIO_DESTROY;
161 }
162
163 return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_PRIO, &opt);
164}
165
166static void
167prio_destroy(struct Qdisc *sch)
168{
169 int prio;
170 struct prio_sched_data *q = qdisc_priv(sch);
171
172 tcf_block_put(q->block);
173 prio_offload(sch, NULL);
174 for (prio = 0; prio < q->bands; prio++)
175 qdisc_put(q->queues[prio]);
176}
177
178static int prio_tune(struct Qdisc *sch, struct nlattr *opt,
179 struct netlink_ext_ack *extack)
180{
181 struct prio_sched_data *q = qdisc_priv(sch);
182 struct Qdisc *queues[TCQ_PRIO_BANDS];
183 int oldbands = q->bands, i;
184 struct tc_prio_qopt *qopt;
185
186 if (nla_len(opt) < sizeof(*qopt))
187 return -EINVAL;
188 qopt = nla_data(opt);
189
190 if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
191 return -EINVAL;
192
193 for (i = 0; i <= TC_PRIO_MAX; i++) {
194 if (qopt->priomap[i] >= qopt->bands)
195 return -EINVAL;
196 }
197
198
199 for (i = oldbands; i < qopt->bands; i++) {
200 queues[i] = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
201 TC_H_MAKE(sch->handle, i + 1),
202 extack);
203 if (!queues[i]) {
204 while (i > oldbands)
205 qdisc_put(queues[--i]);
206 return -ENOMEM;
207 }
208 }
209
210 prio_offload(sch, qopt);
211 sch_tree_lock(sch);
212 q->bands = qopt->bands;
213 memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
214
215 for (i = q->bands; i < oldbands; i++)
216 qdisc_tree_flush_backlog(q->queues[i]);
217
218 for (i = oldbands; i < q->bands; i++) {
219 q->queues[i] = queues[i];
220 if (q->queues[i] != &noop_qdisc)
221 qdisc_hash_add(q->queues[i], true);
222 }
223
224 sch_tree_unlock(sch);
225
226 for (i = q->bands; i < oldbands; i++)
227 qdisc_put(q->queues[i]);
228 return 0;
229}
230
231static int prio_init(struct Qdisc *sch, struct nlattr *opt,
232 struct netlink_ext_ack *extack)
233{
234 struct prio_sched_data *q = qdisc_priv(sch);
235 int err;
236
237 if (!opt)
238 return -EINVAL;
239
240 err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
241 if (err)
242 return err;
243
244 return prio_tune(sch, opt, extack);
245}
246
247static int prio_dump_offload(struct Qdisc *sch)
248{
249 struct tc_prio_qopt_offload hw_stats = {
250 .command = TC_PRIO_STATS,
251 .handle = sch->handle,
252 .parent = sch->parent,
253 {
254 .stats = {
255 .bstats = &sch->bstats,
256 .qstats = &sch->qstats,
257 },
258 },
259 };
260
261 return qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_PRIO, &hw_stats);
262}
263
264static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
265{
266 struct prio_sched_data *q = qdisc_priv(sch);
267 unsigned char *b = skb_tail_pointer(skb);
268 struct tc_prio_qopt opt;
269 int err;
270
271 opt.bands = q->bands;
272 memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX + 1);
273
274 err = prio_dump_offload(sch);
275 if (err)
276 goto nla_put_failure;
277
278 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
279 goto nla_put_failure;
280
281 return skb->len;
282
283nla_put_failure:
284 nlmsg_trim(skb, b);
285 return -1;
286}
287
288static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
289 struct Qdisc **old, struct netlink_ext_ack *extack)
290{
291 struct prio_sched_data *q = qdisc_priv(sch);
292 struct tc_prio_qopt_offload graft_offload;
293 unsigned long band = arg - 1;
294
295 if (!new) {
296 new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
297 TC_H_MAKE(sch->handle, arg), extack);
298 if (!new)
299 new = &noop_qdisc;
300 else
301 qdisc_hash_add(new, true);
302 }
303
304 *old = qdisc_replace(sch, new, &q->queues[band]);
305
306 graft_offload.handle = sch->handle;
307 graft_offload.parent = sch->parent;
308 graft_offload.graft_params.band = band;
309 graft_offload.graft_params.child_handle = new->handle;
310 graft_offload.command = TC_PRIO_GRAFT;
311
312 qdisc_offload_graft_helper(qdisc_dev(sch), sch, new, *old,
313 TC_SETUP_QDISC_PRIO, &graft_offload,
314 extack);
315 return 0;
316}
317
318static struct Qdisc *
319prio_leaf(struct Qdisc *sch, unsigned long arg)
320{
321 struct prio_sched_data *q = qdisc_priv(sch);
322 unsigned long band = arg - 1;
323
324 return q->queues[band];
325}
326
327static unsigned long prio_find(struct Qdisc *sch, u32 classid)
328{
329 struct prio_sched_data *q = qdisc_priv(sch);
330 unsigned long band = TC_H_MIN(classid);
331
332 if (band - 1 >= q->bands)
333 return 0;
334 return band;
335}
336
337static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
338{
339 return prio_find(sch, classid);
340}
341
342
343static void prio_unbind(struct Qdisc *q, unsigned long cl)
344{
345}
346
347static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
348 struct tcmsg *tcm)
349{
350 struct prio_sched_data *q = qdisc_priv(sch);
351
352 tcm->tcm_handle |= TC_H_MIN(cl);
353 tcm->tcm_info = q->queues[cl-1]->handle;
354 return 0;
355}
356
357static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
358 struct gnet_dump *d)
359{
360 struct prio_sched_data *q = qdisc_priv(sch);
361 struct Qdisc *cl_q;
362
363 cl_q = q->queues[cl - 1];
364 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
365 d, cl_q->cpu_bstats, &cl_q->bstats) < 0 ||
366 qdisc_qstats_copy(d, cl_q) < 0)
367 return -1;
368
369 return 0;
370}
371
372static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
373{
374 struct prio_sched_data *q = qdisc_priv(sch);
375 int prio;
376
377 if (arg->stop)
378 return;
379
380 for (prio = 0; prio < q->bands; prio++) {
381 if (arg->count < arg->skip) {
382 arg->count++;
383 continue;
384 }
385 if (arg->fn(sch, prio + 1, arg) < 0) {
386 arg->stop = 1;
387 break;
388 }
389 arg->count++;
390 }
391}
392
393static struct tcf_block *prio_tcf_block(struct Qdisc *sch, unsigned long cl,
394 struct netlink_ext_ack *extack)
395{
396 struct prio_sched_data *q = qdisc_priv(sch);
397
398 if (cl)
399 return NULL;
400 return q->block;
401}
402
403static const struct Qdisc_class_ops prio_class_ops = {
404 .graft = prio_graft,
405 .leaf = prio_leaf,
406 .find = prio_find,
407 .walk = prio_walk,
408 .tcf_block = prio_tcf_block,
409 .bind_tcf = prio_bind,
410 .unbind_tcf = prio_unbind,
411 .dump = prio_dump_class,
412 .dump_stats = prio_dump_class_stats,
413};
414
415static struct Qdisc_ops prio_qdisc_ops __read_mostly = {
416 .next = NULL,
417 .cl_ops = &prio_class_ops,
418 .id = "prio",
419 .priv_size = sizeof(struct prio_sched_data),
420 .enqueue = prio_enqueue,
421 .dequeue = prio_dequeue,
422 .peek = prio_peek,
423 .init = prio_init,
424 .reset = prio_reset,
425 .destroy = prio_destroy,
426 .change = prio_tune,
427 .dump = prio_dump,
428 .owner = THIS_MODULE,
429};
430
431static int __init prio_module_init(void)
432{
433 return register_qdisc(&prio_qdisc_ops);
434}
435
436static void __exit prio_module_exit(void)
437{
438 unregister_qdisc(&prio_qdisc_ops);
439}
440
441module_init(prio_module_init)
442module_exit(prio_module_exit)
443
444MODULE_LICENSE("GPL");
445
