1 /*
2 * net/sched/sch_prio.c Simple 3-band priority "scheduler".
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 * Fixes: 19990609: J Hadi Salim <hadi@nortelnetworks.com>:
11 * Init -- EINVAL when opt undefined
12 */
13
14 #include <linux/config.h>
15 #include <linux/module.h>
16 #include <asm/uaccess.h>
17 #include <asm/system.h>
18 #include <asm/bitops.h>
19 #include <linux/types.h>
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
22 #include <linux/string.h>
23 #include <linux/mm.h>
24 #include <linux/socket.h>
25 #include <linux/sockios.h>
26 #include <linux/in.h>
27 #include <linux/errno.h>
28 #include <linux/interrupt.h>
29 #include <linux/if_ether.h>
30 #include <linux/inet.h>
31 #include <linux/netdevice.h>
32 #include <linux/etherdevice.h>
33 #include <linux/notifier.h>
34 #include <net/ip.h>
35 #include <net/route.h>
36 #include <linux/skbuff.h>
37 #include <net/sock.h>
38 #include <net/pkt_sched.h>
39
40
41 struct prio_sched_data
42 {
43 int bands;
44 struct tcf_proto *filter_list;
45 u8 prio2band[TC_PRIO_MAX+1];
46 struct Qdisc *queues[TCQ_PRIO_BANDS];
47 };
48
49
50 static __inline__ unsigned prio_classify(struct sk_buff *skb, struct Qdisc *sch)
51 {
52 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
53 struct tcf_result res;
54 u32 band;
55
56 band = skb->priority;
57 if (TC_H_MAJ(skb->priority) != sch->handle) {
58 if (!q->filter_list || tc_classify(skb, q->filter_list, &res)) {
59 if (TC_H_MAJ(band))
60 band = 0;
61 return q->prio2band[band&TC_PRIO_MAX];
62 }
63 band = res.classid;
64 }
65 band = TC_H_MIN(band) - 1;
66 return band < q->bands ? band : q->prio2band[0];
67 }
68
69 static int
70 prio_enqueue(struct sk_buff *skb, struct Qdisc* sch)
71 {
72 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
73 struct Qdisc *qdisc;
74 int ret;
75
76 qdisc = q->queues[prio_classify(skb, sch)];
77
78 if ((ret = qdisc->enqueue(skb, qdisc)) == 0) {
79 sch->stats.bytes += skb->len;
80 sch->stats.packets++;
81 sch->q.qlen++;
82 return 0;
83 }
84 sch->stats.drops++;
85 return ret;
86 }
87
88
89 static int
90 prio_requeue(struct sk_buff *skb, struct Qdisc* sch)
91 {
92 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
93 struct Qdisc *qdisc;
94 int ret;
95
96 qdisc = q->queues[prio_classify(skb, sch)];
97
98 if ((ret = qdisc->ops->requeue(skb, qdisc)) == 0) {
99 sch->q.qlen++;
100 return 0;
101 }
102 sch->stats.drops++;
103 return ret;
104 }
105
106
107 static struct sk_buff *
108 prio_dequeue(struct Qdisc* sch)
109 {
110 struct sk_buff *skb;
111 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
112 int prio;
113 struct Qdisc *qdisc;
114
115 for (prio = 0; prio < q->bands; prio++) {
116 qdisc = q->queues[prio];
117 skb = qdisc->dequeue(qdisc);
118 if (skb) {
119 sch->q.qlen--;
120 return skb;
121 }
122 }
123 return NULL;
124
125 }
126
127 static unsigned int prio_drop(struct Qdisc* sch)
128 {
129 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
130 int prio;
131 unsigned int len;
132 struct Qdisc *qdisc;
133
134 for (prio = q->bands-1; prio >= 0; prio--) {
135 qdisc = q->queues[prio];
136 if ((len = qdisc->ops->drop(qdisc)) != 0) {
137 sch->q.qlen--;
138 return len;
139 }
140 }
141 return 0;
142 }
143
144
145 static void
146 prio_reset(struct Qdisc* sch)
147 {
148 int prio;
149 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
150
151 for (prio=0; prio<q->bands; prio++)
152 qdisc_reset(q->queues[prio]);
153 sch->q.qlen = 0;
154 }
155
156 static void
157 prio_destroy(struct Qdisc* sch)
158 {
159 int prio;
160 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
161 struct tcf_proto *tp;
162
163 while ((tp = q->filter_list) != NULL) {
164 q->filter_list = tp->next;
165 tp->ops->destroy(tp);
166 }
167
168 for (prio=0; prio<q->bands; prio++) {
169 qdisc_destroy(q->queues[prio]);
170 q->queues[prio] = &noop_qdisc;
171 }
172 }
173
174 static int prio_tune(struct Qdisc *sch, struct rtattr *opt)
175 {
176 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
177 struct tc_prio_qopt *qopt = RTA_DATA(opt);
178 int i;
179
180 if (opt->rta_len < RTA_LENGTH(sizeof(*qopt)))
181 return -EINVAL;
182 if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
183 return -EINVAL;
184
185 for (i=0; i<=TC_PRIO_MAX; i++) {
186 if (qopt->priomap[i] >= qopt->bands)
187 return -EINVAL;
188 }
189
190 sch_tree_lock(sch);
191 q->bands = qopt->bands;
192 memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
193
194 for (i=q->bands; i<TCQ_PRIO_BANDS; i++) {
195 struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc);
196 if (child != &noop_qdisc)
197 qdisc_destroy(child);
198 }
199 sch_tree_unlock(sch);
200
201 for (i=0; i<=TC_PRIO_MAX; i++) {
202 int band = q->prio2band[i];
203 if (q->queues[band] == &noop_qdisc) {
204 struct Qdisc *child;
205 child = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
206 if (child) {
207 sch_tree_lock(sch);
208 child = xchg(&q->queues[band], child);
209
210 if (child != &noop_qdisc)
211 qdisc_destroy(child);
212 sch_tree_unlock(sch);
213 }
214 }
215 }
216 return 0;
217 }
218
219 static int prio_init(struct Qdisc *sch, struct rtattr *opt)
220 {
221 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
222 int i;
223
224 for (i=0; i<TCQ_PRIO_BANDS; i++)
225 q->queues[i] = &noop_qdisc;
226
227 if (opt == NULL) {
228 return -EINVAL;
229 } else {
230 int err;
231
232 if ((err= prio_tune(sch, opt)) != 0)
233 return err;
234 }
235 return 0;
236 }
237
238 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
239 {
240 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
241 unsigned char *b = skb->tail;
242 struct tc_prio_qopt opt;
243
244 opt.bands = q->bands;
245 memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX+1);
246 RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
247 return skb->len;
248
249 rtattr_failure:
250 skb_trim(skb, b - skb->data);
251 return -1;
252 }
253
254 static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
255 struct Qdisc **old)
256 {
257 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
258 unsigned long band = arg - 1;
259
260 if (band >= q->bands)
261 return -EINVAL;
262
263 if (new == NULL)
264 new = &noop_qdisc;
265
266 sch_tree_lock(sch);
267 *old = q->queues[band];
268 q->queues[band] = new;
269 sch->q.qlen -= (*old)->q.qlen;
270 qdisc_reset(*old);
271 sch_tree_unlock(sch);
272
273 return 0;
274 }
275
276 static struct Qdisc *
277 prio_leaf(struct Qdisc *sch, unsigned long arg)
278 {
279 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
280 unsigned long band = arg - 1;
281
282 if (band >= q->bands)
283 return NULL;
284
285 return q->queues[band];
286 }
287
288 static unsigned long prio_get(struct Qdisc *sch, u32 classid)
289 {
290 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
291 unsigned long band = TC_H_MIN(classid);
292
293 if (band - 1 >= q->bands)
294 return 0;
295 return band;
296 }
297
298 static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
299 {
300 return prio_get(sch, classid);
301 }
302
303
304 static void prio_put(struct Qdisc *q, unsigned long cl)
305 {
306 return;
307 }
308
309 static int prio_change(struct Qdisc *sch, u32 handle, u32 parent, struct rtattr **tca, unsigned long *arg)
310 {
311 unsigned long cl = *arg;
312 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
313
314 if (cl - 1 > q->bands)
315 return -ENOENT;
316 return 0;
317 }
318
319 static int prio_delete(struct Qdisc *sch, unsigned long cl)
320 {
321 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
322 if (cl - 1 > q->bands)
323 return -ENOENT;
324 return 0;
325 }
326
327
328 static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
329 struct tcmsg *tcm)
330 {
331 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
332
333 if (cl - 1 > q->bands)
334 return -ENOENT;
335 tcm->tcm_handle |= TC_H_MIN(cl);
336 if (q->queues[cl-1])
337 tcm->tcm_info = q->queues[cl-1]->handle;
338 return 0;
339 }
340
341 static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
342 {
343 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
344 int prio;
345
346 if (arg->stop)
347 return;
348
349 for (prio = 0; prio < q->bands; prio++) {
350 if (arg->count < arg->skip) {
351 arg->count++;
352 continue;
353 }
354 if (arg->fn(sch, prio+1, arg) < 0) {
355 arg->stop = 1;
356 break;
357 }
358 arg->count++;
359 }
360 }
361
362 static struct tcf_proto ** prio_find_tcf(struct Qdisc *sch, unsigned long cl)
363 {
364 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
365
366 if (cl)
367 return NULL;
368 return &q->filter_list;
369 }
370
371 static struct Qdisc_class_ops prio_class_ops = {
372 .graft = prio_graft,
373 .leaf = prio_leaf,
374 .get = prio_get,
375 .put = prio_put,
376 .change = prio_change,
377 .delete = prio_delete,
378 .walk = prio_walk,
379 .tcf_chain = prio_find_tcf,
380 .bind_tcf = prio_bind,
381 .unbind_tcf = prio_put,
382 .dump = prio_dump_class,
383 };
384
385 struct Qdisc_ops prio_qdisc_ops = {
386 .next = NULL,
387 .cl_ops = &prio_class_ops,
388 .id = "prio",
389 .priv_size = sizeof(struct prio_sched_data),
390 .enqueue = prio_enqueue,
391 .dequeue = prio_dequeue,
392 .requeue = prio_requeue,
393 .drop = prio_drop,
394 .init = prio_init,
395 .reset = prio_reset,
396 .destroy = prio_destroy,
397 .change = prio_tune,
398 .dump = prio_dump,
399 .owner = THIS_MODULE,
400 };
401
402 #ifdef MODULE
403
404 int init_module(void)
405 {
406 return register_qdisc(&prio_qdisc_ops);
407 }
408
409 void cleanup_module(void)
410 {
411 unregister_qdisc(&prio_qdisc_ops);
412 }
413
414 #endif
415 MODULE_LICENSE("GPL");
416
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