blob: 5819dd82630d2a126d2a75a3cd2f5d6a9a3534a8 [file] [log] [blame]
Eric Dumazete13e02a32011-02-23 10:56:17 +00001/*
2 * net/sched/sch_sfb.c Stochastic Fair Blue
3 *
4 * Copyright (c) 2008-2011 Juliusz Chroboczek <jch@pps.jussieu.fr>
5 * Copyright (c) 2011 Eric Dumazet <eric.dumazet@gmail.com>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * version 2 as published by the Free Software Foundation.
10 *
11 * W. Feng, D. Kandlur, D. Saha, K. Shin. Blue:
12 * A New Class of Active Queue Management Algorithms.
13 * U. Michigan CSE-TR-387-99, April 1999.
14 *
15 * http://www.thefengs.com/wuchang/blue/CSE-TR-387-99.pdf
16 *
17 */
18
19#include <linux/module.h>
20#include <linux/types.h>
21#include <linux/kernel.h>
22#include <linux/errno.h>
23#include <linux/skbuff.h>
24#include <linux/random.h>
25#include <linux/jhash.h>
26#include <net/ip.h>
27#include <net/pkt_sched.h>
28#include <net/inet_ecn.h>
Eric Dumazeta00bd462011-11-28 05:25:02 +000029#include <net/flow_keys.h>
Eric Dumazete13e02a32011-02-23 10:56:17 +000030
31/*
32 * SFB uses two B[l][n] : L x N arrays of bins (L levels, N bins per level)
33 * This implementation uses L = 8 and N = 16
34 * This permits us to split one 32bit hash (provided per packet by rxhash or
35 * external classifier) into 8 subhashes of 4 bits.
36 */
37#define SFB_BUCKET_SHIFT 4
38#define SFB_NUMBUCKETS (1 << SFB_BUCKET_SHIFT) /* N bins per Level */
39#define SFB_BUCKET_MASK (SFB_NUMBUCKETS - 1)
40#define SFB_LEVELS (32 / SFB_BUCKET_SHIFT) /* L */
41
42/* SFB algo uses a virtual queue, named "bin" */
43struct sfb_bucket {
44 u16 qlen; /* length of virtual queue */
45 u16 p_mark; /* marking probability */
46};
47
48/* We use a double buffering right before hash change
49 * (Section 4.4 of SFB reference : moving hash functions)
50 */
51struct sfb_bins {
52 u32 perturbation; /* jhash perturbation */
53 struct sfb_bucket bins[SFB_LEVELS][SFB_NUMBUCKETS];
54};
55
56struct sfb_sched_data {
57 struct Qdisc *qdisc;
John Fastabend25d8c0d2014-09-12 20:05:27 -070058 struct tcf_proto __rcu *filter_list;
Eric Dumazete13e02a32011-02-23 10:56:17 +000059 unsigned long rehash_interval;
60 unsigned long warmup_time; /* double buffering warmup time in jiffies */
61 u32 max;
62 u32 bin_size; /* maximum queue length per bin */
63 u32 increment; /* d1 */
64 u32 decrement; /* d2 */
65 u32 limit; /* HARD maximal queue length */
66 u32 penalty_rate;
67 u32 penalty_burst;
68 u32 tokens_avail;
69 unsigned long rehash_time;
70 unsigned long token_time;
71
72 u8 slot; /* current active bins (0 or 1) */
73 bool double_buffering;
74 struct sfb_bins bins[2];
75
76 struct {
77 u32 earlydrop;
78 u32 penaltydrop;
79 u32 bucketdrop;
80 u32 queuedrop;
81 u32 childdrop; /* drops in child qdisc */
82 u32 marked; /* ECN mark */
83 } stats;
84};
85
86/*
87 * Each queued skb might be hashed on one or two bins
88 * We store in skb_cb the two hash values.
89 * (A zero value means double buffering was not used)
90 */
91struct sfb_skb_cb {
92 u32 hashes[2];
93};
94
95static inline struct sfb_skb_cb *sfb_skb_cb(const struct sk_buff *skb)
96{
David S. Miller16bda132012-02-06 15:14:37 -050097 qdisc_cb_private_validate(skb, sizeof(struct sfb_skb_cb));
Eric Dumazete13e02a32011-02-23 10:56:17 +000098 return (struct sfb_skb_cb *)qdisc_skb_cb(skb)->data;
99}
100
101/*
102 * If using 'internal' SFB flow classifier, hash comes from skb rxhash
103 * If using external classifier, hash comes from the classid.
104 */
105static u32 sfb_hash(const struct sk_buff *skb, u32 slot)
106{
107 return sfb_skb_cb(skb)->hashes[slot];
108}
109
110/* Probabilities are coded as Q0.16 fixed-point values,
111 * with 0xFFFF representing 65535/65536 (almost 1.0)
112 * Addition and subtraction are saturating in [0, 65535]
113 */
114static u32 prob_plus(u32 p1, u32 p2)
115{
116 u32 res = p1 + p2;
117
118 return min_t(u32, res, SFB_MAX_PROB);
119}
120
121static u32 prob_minus(u32 p1, u32 p2)
122{
123 return p1 > p2 ? p1 - p2 : 0;
124}
125
126static void increment_one_qlen(u32 sfbhash, u32 slot, struct sfb_sched_data *q)
127{
128 int i;
129 struct sfb_bucket *b = &q->bins[slot].bins[0][0];
130
131 for (i = 0; i < SFB_LEVELS; i++) {
132 u32 hash = sfbhash & SFB_BUCKET_MASK;
133
134 sfbhash >>= SFB_BUCKET_SHIFT;
135 if (b[hash].qlen < 0xFFFF)
136 b[hash].qlen++;
137 b += SFB_NUMBUCKETS; /* next level */
138 }
139}
140
141static void increment_qlen(const struct sk_buff *skb, struct sfb_sched_data *q)
142{
143 u32 sfbhash;
144
145 sfbhash = sfb_hash(skb, 0);
146 if (sfbhash)
147 increment_one_qlen(sfbhash, 0, q);
148
149 sfbhash = sfb_hash(skb, 1);
150 if (sfbhash)
151 increment_one_qlen(sfbhash, 1, q);
152}
153
154static void decrement_one_qlen(u32 sfbhash, u32 slot,
155 struct sfb_sched_data *q)
156{
157 int i;
158 struct sfb_bucket *b = &q->bins[slot].bins[0][0];
159
160 for (i = 0; i < SFB_LEVELS; i++) {
161 u32 hash = sfbhash & SFB_BUCKET_MASK;
162
163 sfbhash >>= SFB_BUCKET_SHIFT;
164 if (b[hash].qlen > 0)
165 b[hash].qlen--;
166 b += SFB_NUMBUCKETS; /* next level */
167 }
168}
169
170static void decrement_qlen(const struct sk_buff *skb, struct sfb_sched_data *q)
171{
172 u32 sfbhash;
173
174 sfbhash = sfb_hash(skb, 0);
175 if (sfbhash)
176 decrement_one_qlen(sfbhash, 0, q);
177
178 sfbhash = sfb_hash(skb, 1);
179 if (sfbhash)
180 decrement_one_qlen(sfbhash, 1, q);
181}
182
183static void decrement_prob(struct sfb_bucket *b, struct sfb_sched_data *q)
184{
185 b->p_mark = prob_minus(b->p_mark, q->decrement);
186}
187
188static void increment_prob(struct sfb_bucket *b, struct sfb_sched_data *q)
189{
190 b->p_mark = prob_plus(b->p_mark, q->increment);
191}
192
193static void sfb_zero_all_buckets(struct sfb_sched_data *q)
194{
195 memset(&q->bins, 0, sizeof(q->bins));
196}
197
198/*
199 * compute max qlen, max p_mark, and avg p_mark
200 */
201static u32 sfb_compute_qlen(u32 *prob_r, u32 *avgpm_r, const struct sfb_sched_data *q)
202{
203 int i;
204 u32 qlen = 0, prob = 0, totalpm = 0;
205 const struct sfb_bucket *b = &q->bins[q->slot].bins[0][0];
206
207 for (i = 0; i < SFB_LEVELS * SFB_NUMBUCKETS; i++) {
208 if (qlen < b->qlen)
209 qlen = b->qlen;
210 totalpm += b->p_mark;
211 if (prob < b->p_mark)
212 prob = b->p_mark;
213 b++;
214 }
215 *prob_r = prob;
216 *avgpm_r = totalpm / (SFB_LEVELS * SFB_NUMBUCKETS);
217 return qlen;
218}
219
220
221static void sfb_init_perturbation(u32 slot, struct sfb_sched_data *q)
222{
Aruna-Hewapathirane63862b52014-01-11 07:15:59 -0500223 q->bins[slot].perturbation = prandom_u32();
Eric Dumazete13e02a32011-02-23 10:56:17 +0000224}
225
226static void sfb_swap_slot(struct sfb_sched_data *q)
227{
228 sfb_init_perturbation(q->slot, q);
229 q->slot ^= 1;
230 q->double_buffering = false;
231}
232
233/* Non elastic flows are allowed to use part of the bandwidth, expressed
234 * in "penalty_rate" packets per second, with "penalty_burst" burst
235 */
236static bool sfb_rate_limit(struct sk_buff *skb, struct sfb_sched_data *q)
237{
238 if (q->penalty_rate == 0 || q->penalty_burst == 0)
239 return true;
240
241 if (q->tokens_avail < 1) {
242 unsigned long age = min(10UL * HZ, jiffies - q->token_time);
243
244 q->tokens_avail = (age * q->penalty_rate) / HZ;
245 if (q->tokens_avail > q->penalty_burst)
246 q->tokens_avail = q->penalty_burst;
247 q->token_time = jiffies;
248 if (q->tokens_avail < 1)
249 return true;
250 }
251
252 q->tokens_avail--;
253 return false;
254}
255
John Fastabend25d8c0d2014-09-12 20:05:27 -0700256static bool sfb_classify(struct sk_buff *skb, struct tcf_proto *fl,
Eric Dumazete13e02a32011-02-23 10:56:17 +0000257 int *qerr, u32 *salt)
258{
259 struct tcf_result res;
260 int result;
261
John Fastabend25d8c0d2014-09-12 20:05:27 -0700262 result = tc_classify(skb, fl, &res);
Eric Dumazete13e02a32011-02-23 10:56:17 +0000263 if (result >= 0) {
264#ifdef CONFIG_NET_CLS_ACT
265 switch (result) {
266 case TC_ACT_STOLEN:
267 case TC_ACT_QUEUED:
268 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
269 case TC_ACT_SHOT:
270 return false;
271 }
272#endif
273 *salt = TC_H_MIN(res.classid);
274 return true;
275 }
276 return false;
277}
278
279static int sfb_enqueue(struct sk_buff *skb, struct Qdisc *sch)
280{
281
282 struct sfb_sched_data *q = qdisc_priv(sch);
283 struct Qdisc *child = q->qdisc;
John Fastabend25d8c0d2014-09-12 20:05:27 -0700284 struct tcf_proto *fl;
Eric Dumazete13e02a32011-02-23 10:56:17 +0000285 int i;
286 u32 p_min = ~0;
287 u32 minqlen = ~0;
288 u32 r, slot, salt, sfbhash;
289 int ret = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
Eric Dumazeta00bd462011-11-28 05:25:02 +0000290 struct flow_keys keys;
Eric Dumazete13e02a32011-02-23 10:56:17 +0000291
Eric Dumazet363437f2011-08-25 06:21:32 +0000292 if (unlikely(sch->q.qlen >= q->limit)) {
John Fastabend25331d62014-09-28 11:53:29 -0700293 qdisc_qstats_overlimit(sch);
Eric Dumazet363437f2011-08-25 06:21:32 +0000294 q->stats.queuedrop++;
295 goto drop;
296 }
297
Eric Dumazete13e02a32011-02-23 10:56:17 +0000298 if (q->rehash_interval > 0) {
299 unsigned long limit = q->rehash_time + q->rehash_interval;
300
301 if (unlikely(time_after(jiffies, limit))) {
302 sfb_swap_slot(q);
303 q->rehash_time = jiffies;
304 } else if (unlikely(!q->double_buffering && q->warmup_time > 0 &&
305 time_after(jiffies, limit - q->warmup_time))) {
306 q->double_buffering = true;
307 }
308 }
309
John Fastabend25d8c0d2014-09-12 20:05:27 -0700310 fl = rcu_dereference_bh(q->filter_list);
311 if (fl) {
Eric Dumazete13e02a32011-02-23 10:56:17 +0000312 /* If using external classifiers, get result and record it. */
John Fastabend25d8c0d2014-09-12 20:05:27 -0700313 if (!sfb_classify(skb, fl, &ret, &salt))
Eric Dumazete13e02a32011-02-23 10:56:17 +0000314 goto other_drop;
Eric Dumazeta00bd462011-11-28 05:25:02 +0000315 keys.src = salt;
316 keys.dst = 0;
317 keys.ports = 0;
Eric Dumazete13e02a32011-02-23 10:56:17 +0000318 } else {
Eric Dumazeta00bd462011-11-28 05:25:02 +0000319 skb_flow_dissect(skb, &keys);
Eric Dumazete13e02a32011-02-23 10:56:17 +0000320 }
321
322 slot = q->slot;
323
Eric Dumazeta00bd462011-11-28 05:25:02 +0000324 sfbhash = jhash_3words((__force u32)keys.dst,
325 (__force u32)keys.src,
326 (__force u32)keys.ports,
327 q->bins[slot].perturbation);
Eric Dumazete13e02a32011-02-23 10:56:17 +0000328 if (!sfbhash)
329 sfbhash = 1;
330 sfb_skb_cb(skb)->hashes[slot] = sfbhash;
331
332 for (i = 0; i < SFB_LEVELS; i++) {
333 u32 hash = sfbhash & SFB_BUCKET_MASK;
334 struct sfb_bucket *b = &q->bins[slot].bins[i][hash];
335
336 sfbhash >>= SFB_BUCKET_SHIFT;
337 if (b->qlen == 0)
338 decrement_prob(b, q);
339 else if (b->qlen >= q->bin_size)
340 increment_prob(b, q);
341 if (minqlen > b->qlen)
342 minqlen = b->qlen;
343 if (p_min > b->p_mark)
344 p_min = b->p_mark;
345 }
346
347 slot ^= 1;
348 sfb_skb_cb(skb)->hashes[slot] = 0;
349
Eric Dumazet363437f2011-08-25 06:21:32 +0000350 if (unlikely(minqlen >= q->max)) {
John Fastabend25331d62014-09-28 11:53:29 -0700351 qdisc_qstats_overlimit(sch);
Eric Dumazet363437f2011-08-25 06:21:32 +0000352 q->stats.bucketdrop++;
Eric Dumazete13e02a32011-02-23 10:56:17 +0000353 goto drop;
354 }
355
356 if (unlikely(p_min >= SFB_MAX_PROB)) {
357 /* Inelastic flow */
358 if (q->double_buffering) {
Eric Dumazeta00bd462011-11-28 05:25:02 +0000359 sfbhash = jhash_3words((__force u32)keys.dst,
360 (__force u32)keys.src,
361 (__force u32)keys.ports,
362 q->bins[slot].perturbation);
Eric Dumazete13e02a32011-02-23 10:56:17 +0000363 if (!sfbhash)
364 sfbhash = 1;
365 sfb_skb_cb(skb)->hashes[slot] = sfbhash;
366
367 for (i = 0; i < SFB_LEVELS; i++) {
368 u32 hash = sfbhash & SFB_BUCKET_MASK;
369 struct sfb_bucket *b = &q->bins[slot].bins[i][hash];
370
371 sfbhash >>= SFB_BUCKET_SHIFT;
372 if (b->qlen == 0)
373 decrement_prob(b, q);
374 else if (b->qlen >= q->bin_size)
375 increment_prob(b, q);
376 }
377 }
378 if (sfb_rate_limit(skb, q)) {
John Fastabend25331d62014-09-28 11:53:29 -0700379 qdisc_qstats_overlimit(sch);
Eric Dumazete13e02a32011-02-23 10:56:17 +0000380 q->stats.penaltydrop++;
381 goto drop;
382 }
383 goto enqueue;
384 }
385
Aruna-Hewapathirane63862b52014-01-11 07:15:59 -0500386 r = prandom_u32() & SFB_MAX_PROB;
Eric Dumazete13e02a32011-02-23 10:56:17 +0000387
388 if (unlikely(r < p_min)) {
389 if (unlikely(p_min > SFB_MAX_PROB / 2)) {
390 /* If we're marking that many packets, then either
391 * this flow is unresponsive, or we're badly congested.
392 * In either case, we want to start dropping packets.
393 */
394 if (r < (p_min - SFB_MAX_PROB / 2) * 2) {
395 q->stats.earlydrop++;
396 goto drop;
397 }
398 }
399 if (INET_ECN_set_ce(skb)) {
400 q->stats.marked++;
401 } else {
402 q->stats.earlydrop++;
403 goto drop;
404 }
405 }
406
407enqueue:
408 ret = qdisc_enqueue(skb, child);
409 if (likely(ret == NET_XMIT_SUCCESS)) {
410 sch->q.qlen++;
411 increment_qlen(skb, q);
412 } else if (net_xmit_drop_count(ret)) {
413 q->stats.childdrop++;
John Fastabend25331d62014-09-28 11:53:29 -0700414 qdisc_qstats_drop(sch);
Eric Dumazete13e02a32011-02-23 10:56:17 +0000415 }
416 return ret;
417
418drop:
419 qdisc_drop(skb, sch);
420 return NET_XMIT_CN;
421other_drop:
422 if (ret & __NET_XMIT_BYPASS)
John Fastabend25331d62014-09-28 11:53:29 -0700423 qdisc_qstats_drop(sch);
Eric Dumazete13e02a32011-02-23 10:56:17 +0000424 kfree_skb(skb);
425 return ret;
426}
427
428static struct sk_buff *sfb_dequeue(struct Qdisc *sch)
429{
430 struct sfb_sched_data *q = qdisc_priv(sch);
431 struct Qdisc *child = q->qdisc;
432 struct sk_buff *skb;
433
434 skb = child->dequeue(q->qdisc);
435
436 if (skb) {
437 qdisc_bstats_update(sch, skb);
438 sch->q.qlen--;
439 decrement_qlen(skb, q);
440 }
441
442 return skb;
443}
444
445static struct sk_buff *sfb_peek(struct Qdisc *sch)
446{
447 struct sfb_sched_data *q = qdisc_priv(sch);
448 struct Qdisc *child = q->qdisc;
449
450 return child->ops->peek(child);
451}
452
453/* No sfb_drop -- impossible since the child doesn't return the dropped skb. */
454
455static void sfb_reset(struct Qdisc *sch)
456{
457 struct sfb_sched_data *q = qdisc_priv(sch);
458
459 qdisc_reset(q->qdisc);
460 sch->q.qlen = 0;
461 q->slot = 0;
462 q->double_buffering = false;
463 sfb_zero_all_buckets(q);
464 sfb_init_perturbation(0, q);
465}
466
467static void sfb_destroy(struct Qdisc *sch)
468{
469 struct sfb_sched_data *q = qdisc_priv(sch);
470
471 tcf_destroy_chain(&q->filter_list);
472 qdisc_destroy(q->qdisc);
473}
474
475static const struct nla_policy sfb_policy[TCA_SFB_MAX + 1] = {
476 [TCA_SFB_PARMS] = { .len = sizeof(struct tc_sfb_qopt) },
477};
478
479static const struct tc_sfb_qopt sfb_default_ops = {
480 .rehash_interval = 600 * MSEC_PER_SEC,
481 .warmup_time = 60 * MSEC_PER_SEC,
482 .limit = 0,
483 .max = 25,
484 .bin_size = 20,
485 .increment = (SFB_MAX_PROB + 500) / 1000, /* 0.1 % */
486 .decrement = (SFB_MAX_PROB + 3000) / 6000,
487 .penalty_rate = 10,
488 .penalty_burst = 20,
489};
490
491static int sfb_change(struct Qdisc *sch, struct nlattr *opt)
492{
493 struct sfb_sched_data *q = qdisc_priv(sch);
494 struct Qdisc *child;
495 struct nlattr *tb[TCA_SFB_MAX + 1];
496 const struct tc_sfb_qopt *ctl = &sfb_default_ops;
497 u32 limit;
498 int err;
499
500 if (opt) {
501 err = nla_parse_nested(tb, TCA_SFB_MAX, opt, sfb_policy);
502 if (err < 0)
503 return -EINVAL;
504
505 if (tb[TCA_SFB_PARMS] == NULL)
506 return -EINVAL;
507
508 ctl = nla_data(tb[TCA_SFB_PARMS]);
509 }
510
511 limit = ctl->limit;
512 if (limit == 0)
513 limit = max_t(u32, qdisc_dev(sch)->tx_queue_len, 1);
514
515 child = fifo_create_dflt(sch, &pfifo_qdisc_ops, limit);
516 if (IS_ERR(child))
517 return PTR_ERR(child);
518
519 sch_tree_lock(sch);
520
521 qdisc_tree_decrease_qlen(q->qdisc, q->qdisc->q.qlen);
522 qdisc_destroy(q->qdisc);
523 q->qdisc = child;
524
525 q->rehash_interval = msecs_to_jiffies(ctl->rehash_interval);
526 q->warmup_time = msecs_to_jiffies(ctl->warmup_time);
527 q->rehash_time = jiffies;
528 q->limit = limit;
529 q->increment = ctl->increment;
530 q->decrement = ctl->decrement;
531 q->max = ctl->max;
532 q->bin_size = ctl->bin_size;
533 q->penalty_rate = ctl->penalty_rate;
534 q->penalty_burst = ctl->penalty_burst;
535 q->tokens_avail = ctl->penalty_burst;
536 q->token_time = jiffies;
537
538 q->slot = 0;
539 q->double_buffering = false;
540 sfb_zero_all_buckets(q);
541 sfb_init_perturbation(0, q);
542 sfb_init_perturbation(1, q);
543
544 sch_tree_unlock(sch);
545
546 return 0;
547}
548
549static int sfb_init(struct Qdisc *sch, struct nlattr *opt)
550{
551 struct sfb_sched_data *q = qdisc_priv(sch);
552
553 q->qdisc = &noop_qdisc;
554 return sfb_change(sch, opt);
555}
556
557static int sfb_dump(struct Qdisc *sch, struct sk_buff *skb)
558{
559 struct sfb_sched_data *q = qdisc_priv(sch);
560 struct nlattr *opts;
561 struct tc_sfb_qopt opt = {
562 .rehash_interval = jiffies_to_msecs(q->rehash_interval),
563 .warmup_time = jiffies_to_msecs(q->warmup_time),
564 .limit = q->limit,
565 .max = q->max,
566 .bin_size = q->bin_size,
567 .increment = q->increment,
568 .decrement = q->decrement,
569 .penalty_rate = q->penalty_rate,
570 .penalty_burst = q->penalty_burst,
571 };
572
573 sch->qstats.backlog = q->qdisc->qstats.backlog;
574 opts = nla_nest_start(skb, TCA_OPTIONS);
Alan Cox7ac29082012-07-12 03:39:11 +0000575 if (opts == NULL)
576 goto nla_put_failure;
David S. Miller1b34ec42012-03-29 05:11:39 -0400577 if (nla_put(skb, TCA_SFB_PARMS, sizeof(opt), &opt))
578 goto nla_put_failure;
Eric Dumazete13e02a32011-02-23 10:56:17 +0000579 return nla_nest_end(skb, opts);
580
581nla_put_failure:
582 nla_nest_cancel(skb, opts);
583 return -EMSGSIZE;
584}
585
586static int sfb_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
587{
588 struct sfb_sched_data *q = qdisc_priv(sch);
589 struct tc_sfb_xstats st = {
590 .earlydrop = q->stats.earlydrop,
591 .penaltydrop = q->stats.penaltydrop,
592 .bucketdrop = q->stats.bucketdrop,
593 .queuedrop = q->stats.queuedrop,
594 .childdrop = q->stats.childdrop,
595 .marked = q->stats.marked,
596 };
597
598 st.maxqlen = sfb_compute_qlen(&st.maxprob, &st.avgprob, q);
599
600 return gnet_stats_copy_app(d, &st, sizeof(st));
601}
602
603static int sfb_dump_class(struct Qdisc *sch, unsigned long cl,
604 struct sk_buff *skb, struct tcmsg *tcm)
605{
606 return -ENOSYS;
607}
608
609static int sfb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
610 struct Qdisc **old)
611{
612 struct sfb_sched_data *q = qdisc_priv(sch);
613
614 if (new == NULL)
615 new = &noop_qdisc;
616
617 sch_tree_lock(sch);
618 *old = q->qdisc;
619 q->qdisc = new;
620 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
621 qdisc_reset(*old);
622 sch_tree_unlock(sch);
623 return 0;
624}
625
626static struct Qdisc *sfb_leaf(struct Qdisc *sch, unsigned long arg)
627{
628 struct sfb_sched_data *q = qdisc_priv(sch);
629
630 return q->qdisc;
631}
632
633static unsigned long sfb_get(struct Qdisc *sch, u32 classid)
634{
635 return 1;
636}
637
638static void sfb_put(struct Qdisc *sch, unsigned long arg)
639{
640}
641
642static int sfb_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
643 struct nlattr **tca, unsigned long *arg)
644{
645 return -ENOSYS;
646}
647
648static int sfb_delete(struct Qdisc *sch, unsigned long cl)
649{
650 return -ENOSYS;
651}
652
653static void sfb_walk(struct Qdisc *sch, struct qdisc_walker *walker)
654{
655 if (!walker->stop) {
656 if (walker->count >= walker->skip)
657 if (walker->fn(sch, 1, walker) < 0) {
658 walker->stop = 1;
659 return;
660 }
661 walker->count++;
662 }
663}
664
John Fastabend25d8c0d2014-09-12 20:05:27 -0700665static struct tcf_proto __rcu **sfb_find_tcf(struct Qdisc *sch,
666 unsigned long cl)
Eric Dumazete13e02a32011-02-23 10:56:17 +0000667{
668 struct sfb_sched_data *q = qdisc_priv(sch);
669
670 if (cl)
671 return NULL;
672 return &q->filter_list;
673}
674
675static unsigned long sfb_bind(struct Qdisc *sch, unsigned long parent,
676 u32 classid)
677{
678 return 0;
679}
680
681
682static const struct Qdisc_class_ops sfb_class_ops = {
683 .graft = sfb_graft,
684 .leaf = sfb_leaf,
685 .get = sfb_get,
686 .put = sfb_put,
687 .change = sfb_change_class,
688 .delete = sfb_delete,
689 .walk = sfb_walk,
690 .tcf_chain = sfb_find_tcf,
691 .bind_tcf = sfb_bind,
692 .unbind_tcf = sfb_put,
693 .dump = sfb_dump_class,
694};
695
696static struct Qdisc_ops sfb_qdisc_ops __read_mostly = {
697 .id = "sfb",
698 .priv_size = sizeof(struct sfb_sched_data),
699 .cl_ops = &sfb_class_ops,
700 .enqueue = sfb_enqueue,
701 .dequeue = sfb_dequeue,
702 .peek = sfb_peek,
703 .init = sfb_init,
704 .reset = sfb_reset,
705 .destroy = sfb_destroy,
706 .change = sfb_change,
707 .dump = sfb_dump,
708 .dump_stats = sfb_dump_stats,
709 .owner = THIS_MODULE,
710};
711
712static int __init sfb_module_init(void)
713{
714 return register_qdisc(&sfb_qdisc_ops);
715}
716
717static void __exit sfb_module_exit(void)
718{
719 unregister_qdisc(&sfb_qdisc_ops);
720}
721
722module_init(sfb_module_init)
723module_exit(sfb_module_exit)
724
725MODULE_DESCRIPTION("Stochastic Fair Blue queue discipline");
726MODULE_AUTHOR("Juliusz Chroboczek");
727MODULE_AUTHOR("Eric Dumazet");
728MODULE_LICENSE("GPL");