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