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