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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * net/sched/sch_red.c Random Early Detection queue. | |
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 | * | |
11 | * Changes: | |
dba051f3 | 12 | * J Hadi Salim 980914: computation fixes |
1da177e4 | 13 | * Alexey Makarenko <makar@phoenix.kharkov.ua> 990814: qave on idle link was calculated incorrectly. |
dba051f3 | 14 | * J Hadi Salim 980816: ECN support |
1da177e4 LT |
15 | */ |
16 | ||
1da177e4 | 17 | #include <linux/module.h> |
1da177e4 LT |
18 | #include <linux/types.h> |
19 | #include <linux/kernel.h> | |
1da177e4 | 20 | #include <linux/skbuff.h> |
1da177e4 | 21 | #include <net/pkt_sched.h> |
602f3baf | 22 | #include <net/pkt_cls.h> |
1da177e4 | 23 | #include <net/inet_ecn.h> |
6b31b28a | 24 | #include <net/red.h> |
1da177e4 LT |
25 | |
26 | ||
6b31b28a | 27 | /* Parameters, settable by user: |
1da177e4 LT |
28 | ----------------------------- |
29 | ||
30 | limit - bytes (must be > qth_max + burst) | |
31 | ||
32 | Hard limit on queue length, should be chosen >qth_max | |
33 | to allow packet bursts. This parameter does not | |
34 | affect the algorithms behaviour and can be chosen | |
35 | arbitrarily high (well, less than ram size) | |
36 | Really, this limit will never be reached | |
37 | if RED works correctly. | |
1da177e4 LT |
38 | */ |
39 | ||
cc7ec456 | 40 | struct red_sched_data { |
6b31b28a TG |
41 | u32 limit; /* HARD maximal queue length */ |
42 | unsigned char flags; | |
8af2a218 | 43 | struct timer_list adapt_timer; |
cdeabbb8 | 44 | struct Qdisc *sch; |
6b31b28a | 45 | struct red_parms parms; |
eeca6688 | 46 | struct red_vars vars; |
6b31b28a | 47 | struct red_stats stats; |
f38c39d6 | 48 | struct Qdisc *qdisc; |
1da177e4 LT |
49 | }; |
50 | ||
6b31b28a | 51 | static inline int red_use_ecn(struct red_sched_data *q) |
1da177e4 | 52 | { |
6b31b28a | 53 | return q->flags & TC_RED_ECN; |
1da177e4 LT |
54 | } |
55 | ||
bdc450a0 TG |
56 | static inline int red_use_harddrop(struct red_sched_data *q) |
57 | { | |
58 | return q->flags & TC_RED_HARDDROP; | |
59 | } | |
60 | ||
520ac30f ED |
61 | static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch, |
62 | struct sk_buff **to_free) | |
1da177e4 LT |
63 | { |
64 | struct red_sched_data *q = qdisc_priv(sch); | |
f38c39d6 PM |
65 | struct Qdisc *child = q->qdisc; |
66 | int ret; | |
1da177e4 | 67 | |
eeca6688 ED |
68 | q->vars.qavg = red_calc_qavg(&q->parms, |
69 | &q->vars, | |
70 | child->qstats.backlog); | |
1da177e4 | 71 | |
eeca6688 ED |
72 | if (red_is_idling(&q->vars)) |
73 | red_end_of_idle_period(&q->vars); | |
1da177e4 | 74 | |
eeca6688 | 75 | switch (red_action(&q->parms, &q->vars, q->vars.qavg)) { |
cc7ec456 ED |
76 | case RED_DONT_MARK: |
77 | break; | |
78 | ||
79 | case RED_PROB_MARK: | |
25331d6c | 80 | qdisc_qstats_overlimit(sch); |
cc7ec456 ED |
81 | if (!red_use_ecn(q) || !INET_ECN_set_ce(skb)) { |
82 | q->stats.prob_drop++; | |
83 | goto congestion_drop; | |
84 | } | |
85 | ||
86 | q->stats.prob_mark++; | |
87 | break; | |
88 | ||
89 | case RED_HARD_MARK: | |
25331d6c | 90 | qdisc_qstats_overlimit(sch); |
cc7ec456 ED |
91 | if (red_use_harddrop(q) || !red_use_ecn(q) || |
92 | !INET_ECN_set_ce(skb)) { | |
93 | q->stats.forced_drop++; | |
94 | goto congestion_drop; | |
95 | } | |
96 | ||
97 | q->stats.forced_mark++; | |
98 | break; | |
1da177e4 LT |
99 | } |
100 | ||
520ac30f | 101 | ret = qdisc_enqueue(skb, child, to_free); |
f38c39d6 | 102 | if (likely(ret == NET_XMIT_SUCCESS)) { |
d7f4f332 | 103 | qdisc_qstats_backlog_inc(sch, skb); |
f38c39d6 | 104 | sch->q.qlen++; |
378a2f09 | 105 | } else if (net_xmit_drop_count(ret)) { |
f38c39d6 | 106 | q->stats.pdrop++; |
25331d6c | 107 | qdisc_qstats_drop(sch); |
f38c39d6 PM |
108 | } |
109 | return ret; | |
6b31b28a TG |
110 | |
111 | congestion_drop: | |
520ac30f | 112 | qdisc_drop(skb, sch, to_free); |
1da177e4 LT |
113 | return NET_XMIT_CN; |
114 | } | |
115 | ||
cc7ec456 | 116 | static struct sk_buff *red_dequeue(struct Qdisc *sch) |
1da177e4 LT |
117 | { |
118 | struct sk_buff *skb; | |
119 | struct red_sched_data *q = qdisc_priv(sch); | |
f38c39d6 | 120 | struct Qdisc *child = q->qdisc; |
1da177e4 | 121 | |
f38c39d6 | 122 | skb = child->dequeue(child); |
9190b3b3 ED |
123 | if (skb) { |
124 | qdisc_bstats_update(sch, skb); | |
d7f4f332 | 125 | qdisc_qstats_backlog_dec(sch, skb); |
f38c39d6 | 126 | sch->q.qlen--; |
9190b3b3 | 127 | } else { |
eeca6688 ED |
128 | if (!red_is_idling(&q->vars)) |
129 | red_start_of_idle_period(&q->vars); | |
9190b3b3 | 130 | } |
9e178ff2 | 131 | return skb; |
1da177e4 LT |
132 | } |
133 | ||
cc7ec456 | 134 | static struct sk_buff *red_peek(struct Qdisc *sch) |
8e3af978 JP |
135 | { |
136 | struct red_sched_data *q = qdisc_priv(sch); | |
137 | struct Qdisc *child = q->qdisc; | |
138 | ||
139 | return child->ops->peek(child); | |
140 | } | |
141 | ||
cc7ec456 | 142 | static void red_reset(struct Qdisc *sch) |
1da177e4 LT |
143 | { |
144 | struct red_sched_data *q = qdisc_priv(sch); | |
145 | ||
f38c39d6 | 146 | qdisc_reset(q->qdisc); |
d7f4f332 | 147 | sch->qstats.backlog = 0; |
f38c39d6 | 148 | sch->q.qlen = 0; |
eeca6688 | 149 | red_restart(&q->vars); |
1da177e4 LT |
150 | } |
151 | ||
602f3baf NF |
152 | static int red_offload(struct Qdisc *sch, bool enable) |
153 | { | |
154 | struct red_sched_data *q = qdisc_priv(sch); | |
155 | struct net_device *dev = qdisc_dev(sch); | |
156 | struct tc_red_qopt_offload opt = { | |
157 | .handle = sch->handle, | |
158 | .parent = sch->parent, | |
159 | }; | |
160 | ||
161 | if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) | |
162 | return -EOPNOTSUPP; | |
163 | ||
164 | if (enable) { | |
165 | opt.command = TC_RED_REPLACE; | |
166 | opt.set.min = q->parms.qth_min >> q->parms.Wlog; | |
167 | opt.set.max = q->parms.qth_max >> q->parms.Wlog; | |
168 | opt.set.probability = q->parms.max_P; | |
169 | opt.set.is_ecn = red_use_ecn(q); | |
170 | } else { | |
171 | opt.command = TC_RED_DESTROY; | |
172 | } | |
173 | ||
174 | return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED, &opt); | |
175 | } | |
176 | ||
f38c39d6 PM |
177 | static void red_destroy(struct Qdisc *sch) |
178 | { | |
179 | struct red_sched_data *q = qdisc_priv(sch); | |
8af2a218 ED |
180 | |
181 | del_timer_sync(&q->adapt_timer); | |
602f3baf | 182 | red_offload(sch, false); |
f38c39d6 PM |
183 | qdisc_destroy(q->qdisc); |
184 | } | |
185 | ||
27a3421e PM |
186 | static const struct nla_policy red_policy[TCA_RED_MAX + 1] = { |
187 | [TCA_RED_PARMS] = { .len = sizeof(struct tc_red_qopt) }, | |
188 | [TCA_RED_STAB] = { .len = RED_STAB_SIZE }, | |
a73ed26b | 189 | [TCA_RED_MAX_P] = { .type = NLA_U32 }, |
27a3421e PM |
190 | }; |
191 | ||
1e90474c | 192 | static int red_change(struct Qdisc *sch, struct nlattr *opt) |
1da177e4 LT |
193 | { |
194 | struct red_sched_data *q = qdisc_priv(sch); | |
1e90474c | 195 | struct nlattr *tb[TCA_RED_MAX + 1]; |
1da177e4 | 196 | struct tc_red_qopt *ctl; |
f38c39d6 | 197 | struct Qdisc *child = NULL; |
cee63723 | 198 | int err; |
a73ed26b | 199 | u32 max_P; |
1da177e4 | 200 | |
cee63723 | 201 | if (opt == NULL) |
dba051f3 TG |
202 | return -EINVAL; |
203 | ||
fceb6435 | 204 | err = nla_parse_nested(tb, TCA_RED_MAX, opt, red_policy, NULL); |
cee63723 PM |
205 | if (err < 0) |
206 | return err; | |
207 | ||
1e90474c | 208 | if (tb[TCA_RED_PARMS] == NULL || |
27a3421e | 209 | tb[TCA_RED_STAB] == NULL) |
1da177e4 LT |
210 | return -EINVAL; |
211 | ||
a73ed26b ED |
212 | max_P = tb[TCA_RED_MAX_P] ? nla_get_u32(tb[TCA_RED_MAX_P]) : 0; |
213 | ||
1e90474c | 214 | ctl = nla_data(tb[TCA_RED_PARMS]); |
8afa10cb NF |
215 | if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog)) |
216 | return -EINVAL; | |
1da177e4 | 217 | |
f38c39d6 | 218 | if (ctl->limit > 0) { |
fb0305ce PM |
219 | child = fifo_create_dflt(sch, &bfifo_qdisc_ops, ctl->limit); |
220 | if (IS_ERR(child)) | |
221 | return PTR_ERR(child); | |
f38c39d6 PM |
222 | } |
223 | ||
49b49971 JK |
224 | if (child != &noop_qdisc) |
225 | qdisc_hash_add(child, true); | |
1da177e4 LT |
226 | sch_tree_lock(sch); |
227 | q->flags = ctl->flags; | |
1da177e4 | 228 | q->limit = ctl->limit; |
5e50da01 | 229 | if (child) { |
2ccccf5f WC |
230 | qdisc_tree_reduce_backlog(q->qdisc, q->qdisc->q.qlen, |
231 | q->qdisc->qstats.backlog); | |
b94c8afc PM |
232 | qdisc_destroy(q->qdisc); |
233 | q->qdisc = child; | |
5e50da01 | 234 | } |
1da177e4 | 235 | |
eeca6688 ED |
236 | red_set_parms(&q->parms, |
237 | ctl->qth_min, ctl->qth_max, ctl->Wlog, | |
a73ed26b ED |
238 | ctl->Plog, ctl->Scell_log, |
239 | nla_data(tb[TCA_RED_STAB]), | |
240 | max_P); | |
eeca6688 | 241 | red_set_vars(&q->vars); |
6b31b28a | 242 | |
8af2a218 ED |
243 | del_timer(&q->adapt_timer); |
244 | if (ctl->flags & TC_RED_ADAPTATIVE) | |
245 | mod_timer(&q->adapt_timer, jiffies + HZ/2); | |
246 | ||
1ee5fa1e | 247 | if (!q->qdisc->q.qlen) |
eeca6688 | 248 | red_start_of_idle_period(&q->vars); |
dba051f3 | 249 | |
1da177e4 | 250 | sch_tree_unlock(sch); |
602f3baf | 251 | red_offload(sch, true); |
1da177e4 LT |
252 | return 0; |
253 | } | |
254 | ||
cdeabbb8 | 255 | static inline void red_adaptative_timer(struct timer_list *t) |
8af2a218 | 256 | { |
cdeabbb8 KC |
257 | struct red_sched_data *q = from_timer(q, t, adapt_timer); |
258 | struct Qdisc *sch = q->sch; | |
8af2a218 ED |
259 | spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch)); |
260 | ||
261 | spin_lock(root_lock); | |
eeca6688 | 262 | red_adaptative_algo(&q->parms, &q->vars); |
8af2a218 ED |
263 | mod_timer(&q->adapt_timer, jiffies + HZ/2); |
264 | spin_unlock(root_lock); | |
265 | } | |
266 | ||
cc7ec456 | 267 | static int red_init(struct Qdisc *sch, struct nlattr *opt) |
1da177e4 | 268 | { |
f38c39d6 PM |
269 | struct red_sched_data *q = qdisc_priv(sch); |
270 | ||
271 | q->qdisc = &noop_qdisc; | |
cdeabbb8 KC |
272 | q->sch = sch; |
273 | timer_setup(&q->adapt_timer, red_adaptative_timer, 0); | |
1da177e4 LT |
274 | return red_change(sch, opt); |
275 | } | |
276 | ||
602f3baf NF |
277 | static int red_dump_offload(struct Qdisc *sch, struct tc_red_qopt *opt) |
278 | { | |
279 | struct net_device *dev = qdisc_dev(sch); | |
280 | struct tc_red_qopt_offload hw_stats = { | |
ee9d3429 | 281 | .command = TC_RED_STATS, |
602f3baf NF |
282 | .handle = sch->handle, |
283 | .parent = sch->parent, | |
ee9d3429 AM |
284 | { |
285 | .stats.bstats = &sch->bstats, | |
286 | .stats.qstats = &sch->qstats, | |
287 | }, | |
602f3baf NF |
288 | }; |
289 | int err; | |
290 | ||
291 | opt->flags &= ~TC_RED_OFFLOADED; | |
292 | if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) | |
293 | return 0; | |
294 | ||
295 | err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED, | |
296 | &hw_stats); | |
297 | if (err == -EOPNOTSUPP) | |
298 | return 0; | |
299 | ||
300 | if (!err) | |
301 | opt->flags |= TC_RED_OFFLOADED; | |
302 | ||
303 | return err; | |
304 | } | |
305 | ||
1da177e4 LT |
306 | static int red_dump(struct Qdisc *sch, struct sk_buff *skb) |
307 | { | |
308 | struct red_sched_data *q = qdisc_priv(sch); | |
1e90474c | 309 | struct nlattr *opts = NULL; |
6b31b28a TG |
310 | struct tc_red_qopt opt = { |
311 | .limit = q->limit, | |
312 | .flags = q->flags, | |
313 | .qth_min = q->parms.qth_min >> q->parms.Wlog, | |
314 | .qth_max = q->parms.qth_max >> q->parms.Wlog, | |
315 | .Wlog = q->parms.Wlog, | |
316 | .Plog = q->parms.Plog, | |
317 | .Scell_log = q->parms.Scell_log, | |
318 | }; | |
602f3baf | 319 | int err; |
1da177e4 | 320 | |
0dfb33a0 | 321 | sch->qstats.backlog = q->qdisc->qstats.backlog; |
602f3baf NF |
322 | err = red_dump_offload(sch, &opt); |
323 | if (err) | |
324 | goto nla_put_failure; | |
325 | ||
1e90474c PM |
326 | opts = nla_nest_start(skb, TCA_OPTIONS); |
327 | if (opts == NULL) | |
328 | goto nla_put_failure; | |
1b34ec43 DM |
329 | if (nla_put(skb, TCA_RED_PARMS, sizeof(opt), &opt) || |
330 | nla_put_u32(skb, TCA_RED_MAX_P, q->parms.max_P)) | |
331 | goto nla_put_failure; | |
1e90474c | 332 | return nla_nest_end(skb, opts); |
1da177e4 | 333 | |
1e90474c | 334 | nla_put_failure: |
bc3ed28c TG |
335 | nla_nest_cancel(skb, opts); |
336 | return -EMSGSIZE; | |
1da177e4 LT |
337 | } |
338 | ||
339 | static int red_dump_stats(struct Qdisc *sch, struct gnet_dump *d) | |
340 | { | |
341 | struct red_sched_data *q = qdisc_priv(sch); | |
602f3baf | 342 | struct net_device *dev = qdisc_dev(sch); |
6b31b28a TG |
343 | struct tc_red_xstats st = { |
344 | .early = q->stats.prob_drop + q->stats.forced_drop, | |
345 | .pdrop = q->stats.pdrop, | |
346 | .other = q->stats.other, | |
347 | .marked = q->stats.prob_mark + q->stats.forced_mark, | |
348 | }; | |
349 | ||
602f3baf NF |
350 | if (tc_can_offload(dev) && dev->netdev_ops->ndo_setup_tc) { |
351 | struct red_stats hw_stats = {0}; | |
352 | struct tc_red_qopt_offload hw_stats_request = { | |
ee9d3429 | 353 | .command = TC_RED_XSTATS, |
602f3baf NF |
354 | .handle = sch->handle, |
355 | .parent = sch->parent, | |
ee9d3429 AM |
356 | { |
357 | .xstats = &hw_stats, | |
358 | }, | |
602f3baf NF |
359 | }; |
360 | if (!dev->netdev_ops->ndo_setup_tc(dev, | |
361 | TC_SETUP_QDISC_RED, | |
362 | &hw_stats_request)) { | |
363 | st.early += hw_stats.prob_drop + hw_stats.forced_drop; | |
364 | st.pdrop += hw_stats.pdrop; | |
365 | st.other += hw_stats.other; | |
366 | st.marked += hw_stats.prob_mark + hw_stats.forced_mark; | |
367 | } | |
368 | } | |
369 | ||
6b31b28a | 370 | return gnet_stats_copy_app(d, &st, sizeof(st)); |
1da177e4 LT |
371 | } |
372 | ||
f38c39d6 PM |
373 | static int red_dump_class(struct Qdisc *sch, unsigned long cl, |
374 | struct sk_buff *skb, struct tcmsg *tcm) | |
375 | { | |
376 | struct red_sched_data *q = qdisc_priv(sch); | |
377 | ||
f38c39d6 PM |
378 | tcm->tcm_handle |= TC_H_MIN(1); |
379 | tcm->tcm_info = q->qdisc->handle; | |
380 | return 0; | |
381 | } | |
382 | ||
383 | static int red_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, | |
384 | struct Qdisc **old) | |
385 | { | |
386 | struct red_sched_data *q = qdisc_priv(sch); | |
387 | ||
388 | if (new == NULL) | |
389 | new = &noop_qdisc; | |
390 | ||
86a7996c | 391 | *old = qdisc_replace(sch, new, &q->qdisc); |
f38c39d6 PM |
392 | return 0; |
393 | } | |
394 | ||
395 | static struct Qdisc *red_leaf(struct Qdisc *sch, unsigned long arg) | |
396 | { | |
397 | struct red_sched_data *q = qdisc_priv(sch); | |
398 | return q->qdisc; | |
399 | } | |
400 | ||
143976ce | 401 | static unsigned long red_find(struct Qdisc *sch, u32 classid) |
f38c39d6 PM |
402 | { |
403 | return 1; | |
404 | } | |
405 | ||
f38c39d6 PM |
406 | static void red_walk(struct Qdisc *sch, struct qdisc_walker *walker) |
407 | { | |
408 | if (!walker->stop) { | |
409 | if (walker->count >= walker->skip) | |
410 | if (walker->fn(sch, 1, walker) < 0) { | |
411 | walker->stop = 1; | |
412 | return; | |
413 | } | |
414 | walker->count++; | |
415 | } | |
416 | } | |
417 | ||
20fea08b | 418 | static const struct Qdisc_class_ops red_class_ops = { |
f38c39d6 PM |
419 | .graft = red_graft, |
420 | .leaf = red_leaf, | |
143976ce | 421 | .find = red_find, |
f38c39d6 | 422 | .walk = red_walk, |
f38c39d6 PM |
423 | .dump = red_dump_class, |
424 | }; | |
425 | ||
20fea08b | 426 | static struct Qdisc_ops red_qdisc_ops __read_mostly = { |
1da177e4 LT |
427 | .id = "red", |
428 | .priv_size = sizeof(struct red_sched_data), | |
f38c39d6 | 429 | .cl_ops = &red_class_ops, |
1da177e4 LT |
430 | .enqueue = red_enqueue, |
431 | .dequeue = red_dequeue, | |
8e3af978 | 432 | .peek = red_peek, |
1da177e4 LT |
433 | .init = red_init, |
434 | .reset = red_reset, | |
f38c39d6 | 435 | .destroy = red_destroy, |
1da177e4 LT |
436 | .change = red_change, |
437 | .dump = red_dump, | |
438 | .dump_stats = red_dump_stats, | |
439 | .owner = THIS_MODULE, | |
440 | }; | |
441 | ||
442 | static int __init red_module_init(void) | |
443 | { | |
444 | return register_qdisc(&red_qdisc_ops); | |
445 | } | |
dba051f3 TG |
446 | |
447 | static void __exit red_module_exit(void) | |
1da177e4 LT |
448 | { |
449 | unregister_qdisc(&red_qdisc_ops); | |
450 | } | |
dba051f3 | 451 | |
1da177e4 LT |
452 | module_init(red_module_init) |
453 | module_exit(red_module_exit) | |
dba051f3 | 454 | |
1da177e4 | 455 | MODULE_LICENSE("GPL"); |