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