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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * net/sched/sch_red.c Random Early Detection queue.
4 *
5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
6 *
7 * Changes:
8 * J Hadi Salim 980914: computation fixes
9 * Alexey Makarenko <makar@phoenix.kharkov.ua> 990814: qave on idle link was calculated incorrectly.
10 * J Hadi Salim 980816: ECN support
11 */
12
13#include <linux/module.h>
14#include <linux/types.h>
15#include <linux/kernel.h>
16#include <linux/skbuff.h>
17#include <net/pkt_sched.h>
18#include <net/pkt_cls.h>
19#include <net/inet_ecn.h>
20#include <net/red.h>
21
22
23/* Parameters, settable by user:
24 -----------------------------
25
26 limit - bytes (must be > qth_max + burst)
27
28 Hard limit on queue length, should be chosen >qth_max
29 to allow packet bursts. This parameter does not
30 affect the algorithms behaviour and can be chosen
31 arbitrarily high (well, less than ram size)
32 Really, this limit will never be reached
33 if RED works correctly.
34 */
35
36struct red_sched_data {
37 u32 limit; /* HARD maximal queue length */
38 unsigned char flags;
39 struct timer_list adapt_timer;
40 struct Qdisc *sch;
41 struct red_parms parms;
42 struct red_vars vars;
43 struct red_stats stats;
44 struct Qdisc *qdisc;
45};
46
47static inline int red_use_ecn(struct red_sched_data *q)
48{
49 return q->flags & TC_RED_ECN;
50}
51
52static inline int red_use_harddrop(struct red_sched_data *q)
53{
54 return q->flags & TC_RED_HARDDROP;
55}
56
57static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch,
58 struct sk_buff **to_free)
59{
60 struct red_sched_data *q = qdisc_priv(sch);
61 struct Qdisc *child = q->qdisc;
62 int ret;
63
64 q->vars.qavg = red_calc_qavg(&q->parms,
65 &q->vars,
66 child->qstats.backlog);
67
68 if (red_is_idling(&q->vars))
69 red_end_of_idle_period(&q->vars);
70
71 switch (red_action(&q->parms, &q->vars, q->vars.qavg)) {
72 case RED_DONT_MARK:
73 break;
74
75 case RED_PROB_MARK:
76 qdisc_qstats_overlimit(sch);
77 if (!red_use_ecn(q) || !INET_ECN_set_ce(skb)) {
78 q->stats.prob_drop++;
79 goto congestion_drop;
80 }
81
82 q->stats.prob_mark++;
83 break;
84
85 case RED_HARD_MARK:
86 qdisc_qstats_overlimit(sch);
87 if (red_use_harddrop(q) || !red_use_ecn(q) ||
88 !INET_ECN_set_ce(skb)) {
89 q->stats.forced_drop++;
90 goto congestion_drop;
91 }
92
93 q->stats.forced_mark++;
94 break;
95 }
96
97 ret = qdisc_enqueue(skb, child, to_free);
98 if (likely(ret == NET_XMIT_SUCCESS)) {
99 qdisc_qstats_backlog_inc(sch, skb);
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, to_free);
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 qdisc_qstats_backlog_dec(sch, skb);
122 sch->q.qlen--;
123 } else {
124 if (!red_is_idling(&q->vars))
125 red_start_of_idle_period(&q->vars);
126 }
127 return skb;
128}
129
130static struct sk_buff *red_peek(struct Qdisc *sch)
131{
132 struct red_sched_data *q = qdisc_priv(sch);
133 struct Qdisc *child = q->qdisc;
134
135 return child->ops->peek(child);
136}
137
138static void red_reset(struct Qdisc *sch)
139{
140 struct red_sched_data *q = qdisc_priv(sch);
141
142 qdisc_reset(q->qdisc);
143 sch->qstats.backlog = 0;
144 sch->q.qlen = 0;
145 red_restart(&q->vars);
146}
147
148static int red_offload(struct Qdisc *sch, bool enable)
149{
150 struct red_sched_data *q = qdisc_priv(sch);
151 struct net_device *dev = qdisc_dev(sch);
152 struct tc_red_qopt_offload opt = {
153 .handle = sch->handle,
154 .parent = sch->parent,
155 };
156
157 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
158 return -EOPNOTSUPP;
159
160 if (enable) {
161 opt.command = TC_RED_REPLACE;
162 opt.set.min = q->parms.qth_min >> q->parms.Wlog;
163 opt.set.max = q->parms.qth_max >> q->parms.Wlog;
164 opt.set.probability = q->parms.max_P;
165 opt.set.limit = q->limit;
166 opt.set.is_ecn = red_use_ecn(q);
167 opt.set.is_harddrop = red_use_harddrop(q);
168 opt.set.qstats = &sch->qstats;
169 } else {
170 opt.command = TC_RED_DESTROY;
171 }
172
173 return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED, &opt);
174}
175
176static void red_destroy(struct Qdisc *sch)
177{
178 struct red_sched_data *q = qdisc_priv(sch);
179
180 del_timer_sync(&q->adapt_timer);
181 red_offload(sch, false);
182 qdisc_put(q->qdisc);
183}
184
185static const struct nla_policy red_policy[TCA_RED_MAX + 1] = {
186 [TCA_RED_PARMS] = { .len = sizeof(struct tc_red_qopt) },
187 [TCA_RED_STAB] = { .len = RED_STAB_SIZE },
188 [TCA_RED_MAX_P] = { .type = NLA_U32 },
189};
190
191static int red_change(struct Qdisc *sch, struct nlattr *opt,
192 struct netlink_ext_ack *extack)
193{
194 struct Qdisc *old_child = NULL, *child = NULL;
195 struct red_sched_data *q = qdisc_priv(sch);
196 struct nlattr *tb[TCA_RED_MAX + 1];
197 struct tc_red_qopt *ctl;
198 int err;
199 u32 max_P;
200
201 if (opt == NULL)
202 return -EINVAL;
203
204 err = nla_parse_nested_deprecated(tb, TCA_RED_MAX, opt, red_policy,
205 NULL);
206 if (err < 0)
207 return err;
208
209 if (tb[TCA_RED_PARMS] == NULL ||
210 tb[TCA_RED_STAB] == NULL)
211 return -EINVAL;
212
213 max_P = tb[TCA_RED_MAX_P] ? nla_get_u32(tb[TCA_RED_MAX_P]) : 0;
214
215 ctl = nla_data(tb[TCA_RED_PARMS]);
216 if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog))
217 return -EINVAL;
218
219 if (ctl->limit > 0) {
220 child = fifo_create_dflt(sch, &bfifo_qdisc_ops, ctl->limit,
221 extack);
222 if (IS_ERR(child))
223 return PTR_ERR(child);
224
225 /* child is fifo, no need to check for noop_qdisc */
226 qdisc_hash_add(child, true);
227 }
228
229 sch_tree_lock(sch);
230 q->flags = ctl->flags;
231 q->limit = ctl->limit;
232 if (child) {
233 qdisc_tree_flush_backlog(q->qdisc);
234 old_child = q->qdisc;
235 q->qdisc = child;
236 }
237
238 red_set_parms(&q->parms,
239 ctl->qth_min, ctl->qth_max, ctl->Wlog,
240 ctl->Plog, ctl->Scell_log,
241 nla_data(tb[TCA_RED_STAB]),
242 max_P);
243 red_set_vars(&q->vars);
244
245 del_timer(&q->adapt_timer);
246 if (ctl->flags & TC_RED_ADAPTATIVE)
247 mod_timer(&q->adapt_timer, jiffies + HZ/2);
248
249 if (!q->qdisc->q.qlen)
250 red_start_of_idle_period(&q->vars);
251
252 sch_tree_unlock(sch);
253
254 red_offload(sch, true);
255
256 if (old_child)
257 qdisc_put(old_child);
258 return 0;
259}
260
261static inline void red_adaptative_timer(struct timer_list *t)
262{
263 struct red_sched_data *q = from_timer(q, t, adapt_timer);
264 struct Qdisc *sch = q->sch;
265 spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch));
266
267 spin_lock(root_lock);
268 red_adaptative_algo(&q->parms, &q->vars);
269 mod_timer(&q->adapt_timer, jiffies + HZ/2);
270 spin_unlock(root_lock);
271}
272
273static int red_init(struct Qdisc *sch, struct nlattr *opt,
274 struct netlink_ext_ack *extack)
275{
276 struct red_sched_data *q = qdisc_priv(sch);
277
278 q->qdisc = &noop_qdisc;
279 q->sch = sch;
280 timer_setup(&q->adapt_timer, red_adaptative_timer, 0);
281 return red_change(sch, opt, extack);
282}
283
284static int red_dump_offload_stats(struct Qdisc *sch)
285{
286 struct tc_red_qopt_offload hw_stats = {
287 .command = TC_RED_STATS,
288 .handle = sch->handle,
289 .parent = sch->parent,
290 {
291 .stats.bstats = &sch->bstats,
292 .stats.qstats = &sch->qstats,
293 },
294 };
295
296 return qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_RED, &hw_stats);
297}
298
299static int red_dump(struct Qdisc *sch, struct sk_buff *skb)
300{
301 struct red_sched_data *q = qdisc_priv(sch);
302 struct nlattr *opts = NULL;
303 struct tc_red_qopt opt = {
304 .limit = q->limit,
305 .flags = q->flags,
306 .qth_min = q->parms.qth_min >> q->parms.Wlog,
307 .qth_max = q->parms.qth_max >> q->parms.Wlog,
308 .Wlog = q->parms.Wlog,
309 .Plog = q->parms.Plog,
310 .Scell_log = q->parms.Scell_log,
311 };
312 int err;
313
314 err = red_dump_offload_stats(sch);
315 if (err)
316 goto nla_put_failure;
317
318 opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
319 if (opts == NULL)
320 goto nla_put_failure;
321 if (nla_put(skb, TCA_RED_PARMS, sizeof(opt), &opt) ||
322 nla_put_u32(skb, TCA_RED_MAX_P, q->parms.max_P))
323 goto nla_put_failure;
324 return nla_nest_end(skb, opts);
325
326nla_put_failure:
327 nla_nest_cancel(skb, opts);
328 return -EMSGSIZE;
329}
330
331static int red_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
332{
333 struct red_sched_data *q = qdisc_priv(sch);
334 struct net_device *dev = qdisc_dev(sch);
335 struct tc_red_xstats st = {0};
336
337 if (sch->flags & TCQ_F_OFFLOADED) {
338 struct tc_red_qopt_offload hw_stats_request = {
339 .command = TC_RED_XSTATS,
340 .handle = sch->handle,
341 .parent = sch->parent,
342 {
343 .xstats = &q->stats,
344 },
345 };
346 dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED,
347 &hw_stats_request);
348 }
349 st.early = q->stats.prob_drop + q->stats.forced_drop;
350 st.pdrop = q->stats.pdrop;
351 st.other = q->stats.other;
352 st.marked = q->stats.prob_mark + q->stats.forced_mark;
353
354 return gnet_stats_copy_app(d, &st, sizeof(st));
355}
356
357static int red_dump_class(struct Qdisc *sch, unsigned long cl,
358 struct sk_buff *skb, struct tcmsg *tcm)
359{
360 struct red_sched_data *q = qdisc_priv(sch);
361
362 tcm->tcm_handle |= TC_H_MIN(1);
363 tcm->tcm_info = q->qdisc->handle;
364 return 0;
365}
366
367static void red_graft_offload(struct Qdisc *sch,
368 struct Qdisc *new, struct Qdisc *old,
369 struct netlink_ext_ack *extack)
370{
371 struct tc_red_qopt_offload graft_offload = {
372 .handle = sch->handle,
373 .parent = sch->parent,
374 .child_handle = new->handle,
375 .command = TC_RED_GRAFT,
376 };
377
378 qdisc_offload_graft_helper(qdisc_dev(sch), sch, new, old,
379 TC_SETUP_QDISC_RED, &graft_offload, extack);
380}
381
382static int red_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
383 struct Qdisc **old, struct netlink_ext_ack *extack)
384{
385 struct red_sched_data *q = qdisc_priv(sch);
386
387 if (new == NULL)
388 new = &noop_qdisc;
389
390 *old = qdisc_replace(sch, new, &q->qdisc);
391
392 red_graft_offload(sch, new, *old, extack);
393 return 0;
394}
395
396static struct Qdisc *red_leaf(struct Qdisc *sch, unsigned long arg)
397{
398 struct red_sched_data *q = qdisc_priv(sch);
399 return q->qdisc;
400}
401
402static unsigned long red_find(struct Qdisc *sch, u32 classid)
403{
404 return 1;
405}
406
407static void red_walk(struct Qdisc *sch, struct qdisc_walker *walker)
408{
409 if (!walker->stop) {
410 if (walker->count >= walker->skip)
411 if (walker->fn(sch, 1, walker) < 0) {
412 walker->stop = 1;
413 return;
414 }
415 walker->count++;
416 }
417}
418
419static const struct Qdisc_class_ops red_class_ops = {
420 .graft = red_graft,
421 .leaf = red_leaf,
422 .find = red_find,
423 .walk = red_walk,
424 .dump = red_dump_class,
425};
426
427static struct Qdisc_ops red_qdisc_ops __read_mostly = {
428 .id = "red",
429 .priv_size = sizeof(struct red_sched_data),
430 .cl_ops = &red_class_ops,
431 .enqueue = red_enqueue,
432 .dequeue = red_dequeue,
433 .peek = red_peek,
434 .init = red_init,
435 .reset = red_reset,
436 .destroy = red_destroy,
437 .change = red_change,
438 .dump = red_dump,
439 .dump_stats = red_dump_stats,
440 .owner = THIS_MODULE,
441};
442
443static int __init red_module_init(void)
444{
445 return register_qdisc(&red_qdisc_ops);
446}
447
448static void __exit red_module_exit(void)
449{
450 unregister_qdisc(&red_qdisc_ops);
451}
452
453module_init(red_module_init)
454module_exit(red_module_exit)
455
456MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * net/sched/sch_red.c Random Early Detection queue.
4 *
5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
6 *
7 * Changes:
8 * J Hadi Salim 980914: computation fixes
9 * Alexey Makarenko <makar@phoenix.kharkov.ua> 990814: qave on idle link was calculated incorrectly.
10 * J Hadi Salim 980816: ECN support
11 */
12
13#include <linux/module.h>
14#include <linux/types.h>
15#include <linux/kernel.h>
16#include <linux/skbuff.h>
17#include <net/pkt_sched.h>
18#include <net/pkt_cls.h>
19#include <net/inet_ecn.h>
20#include <net/red.h>
21
22
23/* Parameters, settable by user:
24 -----------------------------
25
26 limit - bytes (must be > qth_max + burst)
27
28 Hard limit on queue length, should be chosen >qth_max
29 to allow packet bursts. This parameter does not
30 affect the algorithms behaviour and can be chosen
31 arbitrarily high (well, less than ram size)
32 Really, this limit will never be reached
33 if RED works correctly.
34 */
35
36struct red_sched_data {
37 u32 limit; /* HARD maximal queue length */
38
39 unsigned char flags;
40 /* Non-flags in tc_red_qopt.flags. */
41 unsigned char userbits;
42
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 struct tcf_qevent qe_early_drop;
50 struct tcf_qevent qe_mark;
51};
52
53#define TC_RED_SUPPORTED_FLAGS (TC_RED_HISTORIC_FLAGS | TC_RED_NODROP)
54
55static inline int red_use_ecn(struct red_sched_data *q)
56{
57 return q->flags & TC_RED_ECN;
58}
59
60static inline int red_use_harddrop(struct red_sched_data *q)
61{
62 return q->flags & TC_RED_HARDDROP;
63}
64
65static int red_use_nodrop(struct red_sched_data *q)
66{
67 return q->flags & TC_RED_NODROP;
68}
69
70static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch,
71 struct sk_buff **to_free)
72{
73 struct red_sched_data *q = qdisc_priv(sch);
74 struct Qdisc *child = q->qdisc;
75 int ret;
76
77 q->vars.qavg = red_calc_qavg(&q->parms,
78 &q->vars,
79 child->qstats.backlog);
80
81 if (red_is_idling(&q->vars))
82 red_end_of_idle_period(&q->vars);
83
84 switch (red_action(&q->parms, &q->vars, q->vars.qavg)) {
85 case RED_DONT_MARK:
86 break;
87
88 case RED_PROB_MARK:
89 qdisc_qstats_overlimit(sch);
90 if (!red_use_ecn(q)) {
91 q->stats.prob_drop++;
92 goto congestion_drop;
93 }
94
95 if (INET_ECN_set_ce(skb)) {
96 q->stats.prob_mark++;
97 skb = tcf_qevent_handle(&q->qe_mark, sch, skb, to_free, &ret);
98 if (!skb)
99 return NET_XMIT_CN | ret;
100 } else if (!red_use_nodrop(q)) {
101 q->stats.prob_drop++;
102 goto congestion_drop;
103 }
104
105 /* Non-ECT packet in ECN nodrop mode: queue it. */
106 break;
107
108 case RED_HARD_MARK:
109 qdisc_qstats_overlimit(sch);
110 if (red_use_harddrop(q) || !red_use_ecn(q)) {
111 q->stats.forced_drop++;
112 goto congestion_drop;
113 }
114
115 if (INET_ECN_set_ce(skb)) {
116 q->stats.forced_mark++;
117 skb = tcf_qevent_handle(&q->qe_mark, sch, skb, to_free, &ret);
118 if (!skb)
119 return NET_XMIT_CN | ret;
120 } else if (!red_use_nodrop(q)) {
121 q->stats.forced_drop++;
122 goto congestion_drop;
123 }
124
125 /* Non-ECT packet in ECN nodrop mode: queue it. */
126 break;
127 }
128
129 ret = qdisc_enqueue(skb, child, to_free);
130 if (likely(ret == NET_XMIT_SUCCESS)) {
131 qdisc_qstats_backlog_inc(sch, skb);
132 sch->q.qlen++;
133 } else if (net_xmit_drop_count(ret)) {
134 q->stats.pdrop++;
135 qdisc_qstats_drop(sch);
136 }
137 return ret;
138
139congestion_drop:
140 skb = tcf_qevent_handle(&q->qe_early_drop, sch, skb, to_free, &ret);
141 if (!skb)
142 return NET_XMIT_CN | ret;
143
144 qdisc_drop(skb, sch, to_free);
145 return NET_XMIT_CN;
146}
147
148static struct sk_buff *red_dequeue(struct Qdisc *sch)
149{
150 struct sk_buff *skb;
151 struct red_sched_data *q = qdisc_priv(sch);
152 struct Qdisc *child = q->qdisc;
153
154 skb = child->dequeue(child);
155 if (skb) {
156 qdisc_bstats_update(sch, skb);
157 qdisc_qstats_backlog_dec(sch, skb);
158 sch->q.qlen--;
159 } else {
160 if (!red_is_idling(&q->vars))
161 red_start_of_idle_period(&q->vars);
162 }
163 return skb;
164}
165
166static struct sk_buff *red_peek(struct Qdisc *sch)
167{
168 struct red_sched_data *q = qdisc_priv(sch);
169 struct Qdisc *child = q->qdisc;
170
171 return child->ops->peek(child);
172}
173
174static void red_reset(struct Qdisc *sch)
175{
176 struct red_sched_data *q = qdisc_priv(sch);
177
178 qdisc_reset(q->qdisc);
179 sch->qstats.backlog = 0;
180 sch->q.qlen = 0;
181 red_restart(&q->vars);
182}
183
184static int red_offload(struct Qdisc *sch, bool enable)
185{
186 struct red_sched_data *q = qdisc_priv(sch);
187 struct net_device *dev = qdisc_dev(sch);
188 struct tc_red_qopt_offload opt = {
189 .handle = sch->handle,
190 .parent = sch->parent,
191 };
192
193 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
194 return -EOPNOTSUPP;
195
196 if (enable) {
197 opt.command = TC_RED_REPLACE;
198 opt.set.min = q->parms.qth_min >> q->parms.Wlog;
199 opt.set.max = q->parms.qth_max >> q->parms.Wlog;
200 opt.set.probability = q->parms.max_P;
201 opt.set.limit = q->limit;
202 opt.set.is_ecn = red_use_ecn(q);
203 opt.set.is_harddrop = red_use_harddrop(q);
204 opt.set.is_nodrop = red_use_nodrop(q);
205 opt.set.qstats = &sch->qstats;
206 } else {
207 opt.command = TC_RED_DESTROY;
208 }
209
210 return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED, &opt);
211}
212
213static void red_destroy(struct Qdisc *sch)
214{
215 struct red_sched_data *q = qdisc_priv(sch);
216
217 tcf_qevent_destroy(&q->qe_mark, sch);
218 tcf_qevent_destroy(&q->qe_early_drop, sch);
219 del_timer_sync(&q->adapt_timer);
220 red_offload(sch, false);
221 qdisc_put(q->qdisc);
222}
223
224static const struct nla_policy red_policy[TCA_RED_MAX + 1] = {
225 [TCA_RED_UNSPEC] = { .strict_start_type = TCA_RED_FLAGS },
226 [TCA_RED_PARMS] = { .len = sizeof(struct tc_red_qopt) },
227 [TCA_RED_STAB] = { .len = RED_STAB_SIZE },
228 [TCA_RED_MAX_P] = { .type = NLA_U32 },
229 [TCA_RED_FLAGS] = NLA_POLICY_BITFIELD32(TC_RED_SUPPORTED_FLAGS),
230 [TCA_RED_EARLY_DROP_BLOCK] = { .type = NLA_U32 },
231 [TCA_RED_MARK_BLOCK] = { .type = NLA_U32 },
232};
233
234static int __red_change(struct Qdisc *sch, struct nlattr **tb,
235 struct netlink_ext_ack *extack)
236{
237 struct Qdisc *old_child = NULL, *child = NULL;
238 struct red_sched_data *q = qdisc_priv(sch);
239 struct nla_bitfield32 flags_bf;
240 struct tc_red_qopt *ctl;
241 unsigned char userbits;
242 unsigned char flags;
243 int err;
244 u32 max_P;
245
246 if (tb[TCA_RED_PARMS] == NULL ||
247 tb[TCA_RED_STAB] == NULL)
248 return -EINVAL;
249
250 max_P = tb[TCA_RED_MAX_P] ? nla_get_u32(tb[TCA_RED_MAX_P]) : 0;
251
252 ctl = nla_data(tb[TCA_RED_PARMS]);
253 if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog))
254 return -EINVAL;
255
256 err = red_get_flags(ctl->flags, TC_RED_HISTORIC_FLAGS,
257 tb[TCA_RED_FLAGS], TC_RED_SUPPORTED_FLAGS,
258 &flags_bf, &userbits, extack);
259 if (err)
260 return err;
261
262 if (ctl->limit > 0) {
263 child = fifo_create_dflt(sch, &bfifo_qdisc_ops, ctl->limit,
264 extack);
265 if (IS_ERR(child))
266 return PTR_ERR(child);
267
268 /* child is fifo, no need to check for noop_qdisc */
269 qdisc_hash_add(child, true);
270 }
271
272 sch_tree_lock(sch);
273
274 flags = (q->flags & ~flags_bf.selector) | flags_bf.value;
275 err = red_validate_flags(flags, extack);
276 if (err)
277 goto unlock_out;
278
279 q->flags = flags;
280 q->userbits = userbits;
281 q->limit = ctl->limit;
282 if (child) {
283 qdisc_tree_flush_backlog(q->qdisc);
284 old_child = q->qdisc;
285 q->qdisc = child;
286 }
287
288 red_set_parms(&q->parms,
289 ctl->qth_min, ctl->qth_max, ctl->Wlog,
290 ctl->Plog, ctl->Scell_log,
291 nla_data(tb[TCA_RED_STAB]),
292 max_P);
293 red_set_vars(&q->vars);
294
295 del_timer(&q->adapt_timer);
296 if (ctl->flags & TC_RED_ADAPTATIVE)
297 mod_timer(&q->adapt_timer, jiffies + HZ/2);
298
299 if (!q->qdisc->q.qlen)
300 red_start_of_idle_period(&q->vars);
301
302 sch_tree_unlock(sch);
303
304 red_offload(sch, true);
305
306 if (old_child)
307 qdisc_put(old_child);
308 return 0;
309
310unlock_out:
311 sch_tree_unlock(sch);
312 if (child)
313 qdisc_put(child);
314 return err;
315}
316
317static inline void red_adaptative_timer(struct timer_list *t)
318{
319 struct red_sched_data *q = from_timer(q, t, adapt_timer);
320 struct Qdisc *sch = q->sch;
321 spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch));
322
323 spin_lock(root_lock);
324 red_adaptative_algo(&q->parms, &q->vars);
325 mod_timer(&q->adapt_timer, jiffies + HZ/2);
326 spin_unlock(root_lock);
327}
328
329static int red_init(struct Qdisc *sch, struct nlattr *opt,
330 struct netlink_ext_ack *extack)
331{
332 struct red_sched_data *q = qdisc_priv(sch);
333 struct nlattr *tb[TCA_RED_MAX + 1];
334 int err;
335
336 q->qdisc = &noop_qdisc;
337 q->sch = sch;
338 timer_setup(&q->adapt_timer, red_adaptative_timer, 0);
339
340 if (!opt)
341 return -EINVAL;
342
343 err = nla_parse_nested_deprecated(tb, TCA_RED_MAX, opt, red_policy,
344 extack);
345 if (err < 0)
346 return err;
347
348 err = __red_change(sch, tb, extack);
349 if (err)
350 return err;
351
352 err = tcf_qevent_init(&q->qe_early_drop, sch,
353 FLOW_BLOCK_BINDER_TYPE_RED_EARLY_DROP,
354 tb[TCA_RED_EARLY_DROP_BLOCK], extack);
355 if (err)
356 return err;
357
358 return tcf_qevent_init(&q->qe_mark, sch,
359 FLOW_BLOCK_BINDER_TYPE_RED_MARK,
360 tb[TCA_RED_MARK_BLOCK], extack);
361}
362
363static int red_change(struct Qdisc *sch, struct nlattr *opt,
364 struct netlink_ext_ack *extack)
365{
366 struct red_sched_data *q = qdisc_priv(sch);
367 struct nlattr *tb[TCA_RED_MAX + 1];
368 int err;
369
370 if (!opt)
371 return -EINVAL;
372
373 err = nla_parse_nested_deprecated(tb, TCA_RED_MAX, opt, red_policy,
374 extack);
375 if (err < 0)
376 return err;
377
378 err = tcf_qevent_validate_change(&q->qe_early_drop,
379 tb[TCA_RED_EARLY_DROP_BLOCK], extack);
380 if (err)
381 return err;
382
383 err = tcf_qevent_validate_change(&q->qe_mark,
384 tb[TCA_RED_MARK_BLOCK], extack);
385 if (err)
386 return err;
387
388 return __red_change(sch, tb, extack);
389}
390
391static int red_dump_offload_stats(struct Qdisc *sch)
392{
393 struct tc_red_qopt_offload hw_stats = {
394 .command = TC_RED_STATS,
395 .handle = sch->handle,
396 .parent = sch->parent,
397 {
398 .stats.bstats = &sch->bstats,
399 .stats.qstats = &sch->qstats,
400 },
401 };
402
403 return qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_RED, &hw_stats);
404}
405
406static int red_dump(struct Qdisc *sch, struct sk_buff *skb)
407{
408 struct red_sched_data *q = qdisc_priv(sch);
409 struct nlattr *opts = NULL;
410 struct tc_red_qopt opt = {
411 .limit = q->limit,
412 .flags = (q->flags & TC_RED_HISTORIC_FLAGS) |
413 q->userbits,
414 .qth_min = q->parms.qth_min >> q->parms.Wlog,
415 .qth_max = q->parms.qth_max >> q->parms.Wlog,
416 .Wlog = q->parms.Wlog,
417 .Plog = q->parms.Plog,
418 .Scell_log = q->parms.Scell_log,
419 };
420 int err;
421
422 err = red_dump_offload_stats(sch);
423 if (err)
424 goto nla_put_failure;
425
426 opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
427 if (opts == NULL)
428 goto nla_put_failure;
429 if (nla_put(skb, TCA_RED_PARMS, sizeof(opt), &opt) ||
430 nla_put_u32(skb, TCA_RED_MAX_P, q->parms.max_P) ||
431 nla_put_bitfield32(skb, TCA_RED_FLAGS,
432 q->flags, TC_RED_SUPPORTED_FLAGS) ||
433 tcf_qevent_dump(skb, TCA_RED_MARK_BLOCK, &q->qe_mark) ||
434 tcf_qevent_dump(skb, TCA_RED_EARLY_DROP_BLOCK, &q->qe_early_drop))
435 goto nla_put_failure;
436 return nla_nest_end(skb, opts);
437
438nla_put_failure:
439 nla_nest_cancel(skb, opts);
440 return -EMSGSIZE;
441}
442
443static int red_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
444{
445 struct red_sched_data *q = qdisc_priv(sch);
446 struct net_device *dev = qdisc_dev(sch);
447 struct tc_red_xstats st = {0};
448
449 if (sch->flags & TCQ_F_OFFLOADED) {
450 struct tc_red_qopt_offload hw_stats_request = {
451 .command = TC_RED_XSTATS,
452 .handle = sch->handle,
453 .parent = sch->parent,
454 {
455 .xstats = &q->stats,
456 },
457 };
458 dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED,
459 &hw_stats_request);
460 }
461 st.early = q->stats.prob_drop + q->stats.forced_drop;
462 st.pdrop = q->stats.pdrop;
463 st.other = q->stats.other;
464 st.marked = q->stats.prob_mark + q->stats.forced_mark;
465
466 return gnet_stats_copy_app(d, &st, sizeof(st));
467}
468
469static int red_dump_class(struct Qdisc *sch, unsigned long cl,
470 struct sk_buff *skb, struct tcmsg *tcm)
471{
472 struct red_sched_data *q = qdisc_priv(sch);
473
474 tcm->tcm_handle |= TC_H_MIN(1);
475 tcm->tcm_info = q->qdisc->handle;
476 return 0;
477}
478
479static void red_graft_offload(struct Qdisc *sch,
480 struct Qdisc *new, struct Qdisc *old,
481 struct netlink_ext_ack *extack)
482{
483 struct tc_red_qopt_offload graft_offload = {
484 .handle = sch->handle,
485 .parent = sch->parent,
486 .child_handle = new->handle,
487 .command = TC_RED_GRAFT,
488 };
489
490 qdisc_offload_graft_helper(qdisc_dev(sch), sch, new, old,
491 TC_SETUP_QDISC_RED, &graft_offload, extack);
492}
493
494static int red_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
495 struct Qdisc **old, struct netlink_ext_ack *extack)
496{
497 struct red_sched_data *q = qdisc_priv(sch);
498
499 if (new == NULL)
500 new = &noop_qdisc;
501
502 *old = qdisc_replace(sch, new, &q->qdisc);
503
504 red_graft_offload(sch, new, *old, extack);
505 return 0;
506}
507
508static struct Qdisc *red_leaf(struct Qdisc *sch, unsigned long arg)
509{
510 struct red_sched_data *q = qdisc_priv(sch);
511 return q->qdisc;
512}
513
514static unsigned long red_find(struct Qdisc *sch, u32 classid)
515{
516 return 1;
517}
518
519static void red_walk(struct Qdisc *sch, struct qdisc_walker *walker)
520{
521 if (!walker->stop) {
522 if (walker->count >= walker->skip)
523 if (walker->fn(sch, 1, walker) < 0) {
524 walker->stop = 1;
525 return;
526 }
527 walker->count++;
528 }
529}
530
531static const struct Qdisc_class_ops red_class_ops = {
532 .graft = red_graft,
533 .leaf = red_leaf,
534 .find = red_find,
535 .walk = red_walk,
536 .dump = red_dump_class,
537};
538
539static struct Qdisc_ops red_qdisc_ops __read_mostly = {
540 .id = "red",
541 .priv_size = sizeof(struct red_sched_data),
542 .cl_ops = &red_class_ops,
543 .enqueue = red_enqueue,
544 .dequeue = red_dequeue,
545 .peek = red_peek,
546 .init = red_init,
547 .reset = red_reset,
548 .destroy = red_destroy,
549 .change = red_change,
550 .dump = red_dump,
551 .dump_stats = red_dump_stats,
552 .owner = THIS_MODULE,
553};
554
555static int __init red_module_init(void)
556{
557 return register_qdisc(&red_qdisc_ops);
558}
559
560static void __exit red_module_exit(void)
561{
562 unregister_qdisc(&red_qdisc_ops);
563}
564
565module_init(red_module_init)
566module_exit(red_module_exit)
567
568MODULE_LICENSE("GPL");