]>
Commit | Line | Data |
---|---|---|
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/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 | ||
25 | struct 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 | ||
33 | static struct Qdisc * | |
34 | prio_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 | ||
69 | static int | |
70 | prio_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 | ||
97 | static 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 | ||
111 | static 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 | ||
130 | static void | |
131 | prio_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 | ||
142 | static void | |
143 | prio_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 | ||
153 | static 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 | /* Before commit, make sure we can allocate all new qdiscs */ | |
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 | ||
198 | sch_tree_unlock(sch); | |
199 | return 0; | |
200 | } | |
201 | ||
202 | static int prio_init(struct Qdisc *sch, struct nlattr *opt) | |
203 | { | |
204 | if (!opt) | |
205 | return -EINVAL; | |
206 | ||
207 | return prio_tune(sch, opt); | |
208 | } | |
209 | ||
210 | static int prio_dump(struct Qdisc *sch, struct sk_buff *skb) | |
211 | { | |
212 | struct prio_sched_data *q = qdisc_priv(sch); | |
213 | unsigned char *b = skb_tail_pointer(skb); | |
214 | struct tc_prio_qopt opt; | |
215 | ||
216 | opt.bands = q->bands; | |
217 | memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX + 1); | |
218 | ||
219 | if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt)) | |
220 | goto nla_put_failure; | |
221 | ||
222 | return skb->len; | |
223 | ||
224 | nla_put_failure: | |
225 | nlmsg_trim(skb, b); | |
226 | return -1; | |
227 | } | |
228 | ||
229 | static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, | |
230 | struct Qdisc **old) | |
231 | { | |
232 | struct prio_sched_data *q = qdisc_priv(sch); | |
233 | unsigned long band = arg - 1; | |
234 | ||
235 | if (new == NULL) | |
236 | new = &noop_qdisc; | |
237 | ||
238 | *old = qdisc_replace(sch, new, &q->queues[band]); | |
239 | return 0; | |
240 | } | |
241 | ||
242 | static struct Qdisc * | |
243 | prio_leaf(struct Qdisc *sch, unsigned long arg) | |
244 | { | |
245 | struct prio_sched_data *q = qdisc_priv(sch); | |
246 | unsigned long band = arg - 1; | |
247 | ||
248 | return q->queues[band]; | |
249 | } | |
250 | ||
251 | static unsigned long prio_get(struct Qdisc *sch, u32 classid) | |
252 | { | |
253 | struct prio_sched_data *q = qdisc_priv(sch); | |
254 | unsigned long band = TC_H_MIN(classid); | |
255 | ||
256 | if (band - 1 >= q->bands) | |
257 | return 0; | |
258 | return band; | |
259 | } | |
260 | ||
261 | static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid) | |
262 | { | |
263 | return prio_get(sch, classid); | |
264 | } | |
265 | ||
266 | ||
267 | static void prio_put(struct Qdisc *q, unsigned long cl) | |
268 | { | |
269 | } | |
270 | ||
271 | static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb, | |
272 | struct tcmsg *tcm) | |
273 | { | |
274 | struct prio_sched_data *q = qdisc_priv(sch); | |
275 | ||
276 | tcm->tcm_handle |= TC_H_MIN(cl); | |
277 | tcm->tcm_info = q->queues[cl-1]->handle; | |
278 | return 0; | |
279 | } | |
280 | ||
281 | static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl, | |
282 | struct gnet_dump *d) | |
283 | { | |
284 | struct prio_sched_data *q = qdisc_priv(sch); | |
285 | struct Qdisc *cl_q; | |
286 | ||
287 | cl_q = q->queues[cl - 1]; | |
288 | if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), | |
289 | d, NULL, &cl_q->bstats) < 0 || | |
290 | gnet_stats_copy_queue(d, NULL, &cl_q->qstats, cl_q->q.qlen) < 0) | |
291 | return -1; | |
292 | ||
293 | return 0; | |
294 | } | |
295 | ||
296 | static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg) | |
297 | { | |
298 | struct prio_sched_data *q = qdisc_priv(sch); | |
299 | int prio; | |
300 | ||
301 | if (arg->stop) | |
302 | return; | |
303 | ||
304 | for (prio = 0; prio < q->bands; prio++) { | |
305 | if (arg->count < arg->skip) { | |
306 | arg->count++; | |
307 | continue; | |
308 | } | |
309 | if (arg->fn(sch, prio + 1, arg) < 0) { | |
310 | arg->stop = 1; | |
311 | break; | |
312 | } | |
313 | arg->count++; | |
314 | } | |
315 | } | |
316 | ||
317 | static struct tcf_proto __rcu **prio_find_tcf(struct Qdisc *sch, | |
318 | unsigned long cl) | |
319 | { | |
320 | struct prio_sched_data *q = qdisc_priv(sch); | |
321 | ||
322 | if (cl) | |
323 | return NULL; | |
324 | return &q->filter_list; | |
325 | } | |
326 | ||
327 | static const struct Qdisc_class_ops prio_class_ops = { | |
328 | .graft = prio_graft, | |
329 | .leaf = prio_leaf, | |
330 | .get = prio_get, | |
331 | .put = prio_put, | |
332 | .walk = prio_walk, | |
333 | .tcf_chain = prio_find_tcf, | |
334 | .bind_tcf = prio_bind, | |
335 | .unbind_tcf = prio_put, | |
336 | .dump = prio_dump_class, | |
337 | .dump_stats = prio_dump_class_stats, | |
338 | }; | |
339 | ||
340 | static struct Qdisc_ops prio_qdisc_ops __read_mostly = { | |
341 | .next = NULL, | |
342 | .cl_ops = &prio_class_ops, | |
343 | .id = "prio", | |
344 | .priv_size = sizeof(struct prio_sched_data), | |
345 | .enqueue = prio_enqueue, | |
346 | .dequeue = prio_dequeue, | |
347 | .peek = prio_peek, | |
348 | .init = prio_init, | |
349 | .reset = prio_reset, | |
350 | .destroy = prio_destroy, | |
351 | .change = prio_tune, | |
352 | .dump = prio_dump, | |
353 | .owner = THIS_MODULE, | |
354 | }; | |
355 | ||
356 | static int __init prio_module_init(void) | |
357 | { | |
358 | return register_qdisc(&prio_qdisc_ops); | |
359 | } | |
360 | ||
361 | static void __exit prio_module_exit(void) | |
362 | { | |
363 | unregister_qdisc(&prio_qdisc_ops); | |
364 | } | |
365 | ||
366 | module_init(prio_module_init) | |
367 | module_exit(prio_module_exit) | |
368 | ||
369 | MODULE_LICENSE("GPL"); |