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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 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, struct sk_buff **to_free)
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, to_free);
87 if (ret == NET_XMIT_SUCCESS) {
88 qdisc_qstats_backlog_inc(sch, skb);
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 void
143prio_destroy(struct Qdisc *sch)
144{
145 int prio;
146 struct prio_sched_data *q = qdisc_priv(sch);
147
148 tcf_destroy_chain(&q->filter_list);
149 for (prio = 0; prio < q->bands; prio++)
150 qdisc_destroy(q->queues[prio]);
151}
152
153static int prio_tune(struct Qdisc *sch, struct nlattr *opt)
154{
155 struct prio_sched_data *q = qdisc_priv(sch);
156 struct Qdisc *queues[TCQ_PRIO_BANDS];
157 int oldbands = q->bands, i;
158 struct tc_prio_qopt *qopt;
159
160 if (nla_len(opt) < sizeof(*qopt))
161 return -EINVAL;
162 qopt = nla_data(opt);
163
164 if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
165 return -EINVAL;
166
167 for (i = 0; i <= TC_PRIO_MAX; i++) {
168 if (qopt->priomap[i] >= qopt->bands)
169 return -EINVAL;
170 }
171
172
173 for (i = oldbands; i < qopt->bands; i++) {
174 queues[i] = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
175 TC_H_MAKE(sch->handle, i + 1));
176 if (!queues[i]) {
177 while (i > oldbands)
178 qdisc_destroy(queues[--i]);
179 return -ENOMEM;
180 }
181 }
182
183 sch_tree_lock(sch);
184 q->bands = qopt->bands;
185 memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
186
187 for (i = q->bands; i < oldbands; i++) {
188 struct Qdisc *child = q->queues[i];
189
190 qdisc_tree_reduce_backlog(child, child->q.qlen,
191 child->qstats.backlog);
192 qdisc_destroy(child);
193 }
194
195 for (i = oldbands; i < q->bands; i++) {
196 q->queues[i] = queues[i];
197 if (q->queues[i] != &noop_qdisc)
198 qdisc_hash_add(q->queues[i], true);
199 }
200
201 sch_tree_unlock(sch);
202 return 0;
203}
204
205static int prio_init(struct Qdisc *sch, struct nlattr *opt)
206{
207 if (!opt)
208 return -EINVAL;
209
210 return prio_tune(sch, opt);
211}
212
213static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
214{
215 struct prio_sched_data *q = qdisc_priv(sch);
216 unsigned char *b = skb_tail_pointer(skb);
217 struct tc_prio_qopt opt;
218
219 opt.bands = q->bands;
220 memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX + 1);
221
222 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
223 goto nla_put_failure;
224
225 return skb->len;
226
227nla_put_failure:
228 nlmsg_trim(skb, b);
229 return -1;
230}
231
232static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
233 struct Qdisc **old)
234{
235 struct prio_sched_data *q = qdisc_priv(sch);
236 unsigned long band = arg - 1;
237
238 if (new == NULL)
239 new = &noop_qdisc;
240
241 *old = qdisc_replace(sch, new, &q->queues[band]);
242 return 0;
243}
244
245static struct Qdisc *
246prio_leaf(struct Qdisc *sch, unsigned long arg)
247{
248 struct prio_sched_data *q = qdisc_priv(sch);
249 unsigned long band = arg - 1;
250
251 return q->queues[band];
252}
253
254static unsigned long prio_get(struct Qdisc *sch, u32 classid)
255{
256 struct prio_sched_data *q = qdisc_priv(sch);
257 unsigned long band = TC_H_MIN(classid);
258
259 if (band - 1 >= q->bands)
260 return 0;
261 return band;
262}
263
264static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
265{
266 return prio_get(sch, classid);
267}
268
269
270static void prio_put(struct Qdisc *q, unsigned long cl)
271{
272}
273
274static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
275 struct tcmsg *tcm)
276{
277 struct prio_sched_data *q = qdisc_priv(sch);
278
279 tcm->tcm_handle |= TC_H_MIN(cl);
280 tcm->tcm_info = q->queues[cl-1]->handle;
281 return 0;
282}
283
284static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
285 struct gnet_dump *d)
286{
287 struct prio_sched_data *q = qdisc_priv(sch);
288 struct Qdisc *cl_q;
289
290 cl_q = q->queues[cl - 1];
291 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
292 d, NULL, &cl_q->bstats) < 0 ||
293 gnet_stats_copy_queue(d, NULL, &cl_q->qstats, cl_q->q.qlen) < 0)
294 return -1;
295
296 return 0;
297}
298
299static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
300{
301 struct prio_sched_data *q = qdisc_priv(sch);
302 int prio;
303
304 if (arg->stop)
305 return;
306
307 for (prio = 0; prio < q->bands; prio++) {
308 if (arg->count < arg->skip) {
309 arg->count++;
310 continue;
311 }
312 if (arg->fn(sch, prio + 1, arg) < 0) {
313 arg->stop = 1;
314 break;
315 }
316 arg->count++;
317 }
318}
319
320static struct tcf_proto __rcu **prio_find_tcf(struct Qdisc *sch,
321 unsigned long cl)
322{
323 struct prio_sched_data *q = qdisc_priv(sch);
324
325 if (cl)
326 return NULL;
327 return &q->filter_list;
328}
329
330static const struct Qdisc_class_ops prio_class_ops = {
331 .graft = prio_graft,
332 .leaf = prio_leaf,
333 .get = prio_get,
334 .put = prio_put,
335 .walk = prio_walk,
336 .tcf_chain = prio_find_tcf,
337 .bind_tcf = prio_bind,
338 .unbind_tcf = prio_put,
339 .dump = prio_dump_class,
340 .dump_stats = prio_dump_class_stats,
341};
342
343static struct Qdisc_ops prio_qdisc_ops __read_mostly = {
344 .next = NULL,
345 .cl_ops = &prio_class_ops,
346 .id = "prio",
347 .priv_size = sizeof(struct prio_sched_data),
348 .enqueue = prio_enqueue,
349 .dequeue = prio_dequeue,
350 .peek = prio_peek,
351 .init = prio_init,
352 .reset = prio_reset,
353 .destroy = prio_destroy,
354 .change = prio_tune,
355 .dump = prio_dump,
356 .owner = THIS_MODULE,
357};
358
359static int __init prio_module_init(void)
360{
361 return register_qdisc(&prio_qdisc_ops);
362}
363
364static void __exit prio_module_exit(void)
365{
366 unregister_qdisc(&prio_qdisc_ops);
367}
368
369module_init(prio_module_init)
370module_exit(prio_module_exit)
371
372MODULE_LICENSE("GPL");
373
