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 int
128 prio_drop(struct Qdisc* sch)
129 {
130 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
131 int prio;
132 struct Qdisc *qdisc;
133
134 for (prio = q->bands-1; prio >= 0; prio--) {
135 qdisc = q->queues[prio];
136 if (qdisc->ops->drop(qdisc)) {
137 sch->q.qlen--;
138 return 1;
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
162 for (prio=0; prio<q->bands; prio++) {
163 qdisc_destroy(q->queues[prio]);
164 q->queues[prio] = &noop_qdisc;
165 }
166 MOD_DEC_USE_COUNT;
167 }
168
169 static int prio_tune(struct Qdisc *sch, struct rtattr *opt)
170 {
171 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
172 struct tc_prio_qopt *qopt = RTA_DATA(opt);
173 int i;
174
175 if (opt->rta_len < RTA_LENGTH(sizeof(*qopt)))
176 return -EINVAL;
177 if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
178 return -EINVAL;
179
180 for (i=0; i<=TC_PRIO_MAX; i++) {
181 if (qopt->priomap[i] >= qopt->bands)
182 return -EINVAL;
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<TCQ_PRIO_BANDS; i++) {
190 struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc);
191 if (child != &noop_qdisc)
192 qdisc_destroy(child);
193 }
194 sch_tree_unlock(sch);
195
196 for (i=0; i<=TC_PRIO_MAX; i++) {
197 int band = q->prio2band[i];
198 if (q->queues[band] == &noop_qdisc) {
199 struct Qdisc *child;
200 child = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
201 if (child) {
202 sch_tree_lock(sch);
203 child = xchg(&q->queues[band], child);
204
205 if (child != &noop_qdisc)
206 qdisc_destroy(child);
207 sch_tree_unlock(sch);
208 }
209 }
210 }
211 return 0;
212 }
213
214 static int prio_init(struct Qdisc *sch, struct rtattr *opt)
215 {
216 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
217 int i;
218
219 for (i=0; i<TCQ_PRIO_BANDS; i++)
220 q->queues[i] = &noop_qdisc;
221
222 if (opt == NULL) {
223 return -EINVAL;
224 } else {
225 int err;
226
227 if ((err= prio_tune(sch, opt)) != 0)
228 return err;
229 }
230 MOD_INC_USE_COUNT;
231 return 0;
232 }
233
234 #ifdef CONFIG_RTNETLINK
235 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
236 {
237 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
238 unsigned char *b = skb->tail;
239 struct tc_prio_qopt opt;
240
241 opt.bands = q->bands;
242 memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX+1);
243 RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
244 return skb->len;
245
246 rtattr_failure:
247 skb_trim(skb, b - skb->data);
248 return -1;
249 }
250 #endif
251
252 static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
253 struct Qdisc **old)
254 {
255 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
256 unsigned long band = arg - 1;
257
258 if (band >= q->bands)
259 return -EINVAL;
260
261 if (new == NULL)
262 new = &noop_qdisc;
263
264 sch_tree_lock(sch);
265 *old = q->queues[band];
266 q->queues[band] = new;
267 qdisc_reset(*old);
268 sch_tree_unlock(sch);
269
270 return 0;
271 }
272
273 static struct Qdisc *
274 prio_leaf(struct Qdisc *sch, unsigned long arg)
275 {
276 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
277 unsigned long band = arg - 1;
278
279 if (band >= q->bands)
280 return NULL;
281
282 return q->queues[band];
283 }
284
285 static unsigned long prio_get(struct Qdisc *sch, u32 classid)
286 {
287 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
288 unsigned long band = TC_H_MIN(classid);
289
290 if (band - 1 >= q->bands)
291 return 0;
292 return band;
293 }
294
295 static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
296 {
297 return prio_get(sch, classid);
298 }
299
300
301 static void prio_put(struct Qdisc *q, unsigned long cl)
302 {
303 return;
304 }
305
306 static int prio_change(struct Qdisc *sch, u32 handle, u32 parent, struct rtattr **tca, unsigned long *arg)
307 {
308 unsigned long cl = *arg;
309 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
310
311 if (cl - 1 > q->bands)
312 return -ENOENT;
313 return 0;
314 }
315
316 static int prio_delete(struct Qdisc *sch, unsigned long cl)
317 {
318 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
319 if (cl - 1 > q->bands)
320 return -ENOENT;
321 return 0;
322 }
323
324
325 #ifdef CONFIG_RTNETLINK
326 static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
327 struct tcmsg *tcm)
328 {
329 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
330
331 if (cl - 1 > q->bands)
332 return -ENOENT;
333 if (q->queues[cl-1])
334 tcm->tcm_info = q->queues[cl-1]->handle;
335 return 0;
336 }
337 #endif
338
339 static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
340 {
341 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
342 int prio;
343
344 if (arg->stop)
345 return;
346
347 for (prio = 0; prio < q->bands; prio++) {
348 if (arg->count < arg->skip) {
349 arg->count++;
350 continue;
351 }
352 if (arg->fn(sch, prio+1, arg) < 0) {
353 arg->stop = 1;
354 break;
355 }
356 arg->count++;
357 }
358 }
359
360 static struct tcf_proto ** prio_find_tcf(struct Qdisc *sch, unsigned long cl)
361 {
362 struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
363
364 if (cl)
365 return NULL;
366 return &q->filter_list;
367 }
368
369 static struct Qdisc_class_ops prio_class_ops =
370 {
371 prio_graft,
372 prio_leaf,
373
374 prio_get,
375 prio_put,
376 prio_change,
377 prio_delete,
378 prio_walk,
379
380 prio_find_tcf,
381 prio_bind,
382 prio_put,
383
384 #ifdef CONFIG_RTNETLINK
385 prio_dump_class,
386 #endif
387 };
388
389 struct Qdisc_ops prio_qdisc_ops =
390 {
391 NULL,
392 &prio_class_ops,
393 "prio",
394 sizeof(struct prio_sched_data),
395
396 prio_enqueue,
397 prio_dequeue,
398 prio_requeue,
399 prio_drop,
400
401 prio_init,
402 prio_reset,
403 prio_destroy,
404 prio_tune,
405
406 #ifdef CONFIG_RTNETLINK
407 prio_dump,
408 #endif
409 };
410
411 #ifdef MODULE
412
413 int init_module(void)
414 {
415 return register_qdisc(&prio_qdisc_ops);
416 }
417
418 void cleanup_module(void)
419 {
420 unregister_qdisc(&prio_qdisc_ops);
421 }
422
423 #endif
424
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