Loading...
Note: File does not exist in v4.6.
1// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2
3/* COMMON Applications Kept Enhanced (CAKE) discipline
4 *
5 * Copyright (C) 2014-2018 Jonathan Morton <chromatix99@gmail.com>
6 * Copyright (C) 2015-2018 Toke Høiland-Jørgensen <toke@toke.dk>
7 * Copyright (C) 2014-2018 Dave Täht <dave.taht@gmail.com>
8 * Copyright (C) 2015-2018 Sebastian Moeller <moeller0@gmx.de>
9 * (C) 2015-2018 Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>
10 * Copyright (C) 2017-2018 Ryan Mounce <ryan@mounce.com.au>
11 *
12 * The CAKE Principles:
13 * (or, how to have your cake and eat it too)
14 *
15 * This is a combination of several shaping, AQM and FQ techniques into one
16 * easy-to-use package:
17 *
18 * - An overall bandwidth shaper, to move the bottleneck away from dumb CPE
19 * equipment and bloated MACs. This operates in deficit mode (as in sch_fq),
20 * eliminating the need for any sort of burst parameter (eg. token bucket
21 * depth). Burst support is limited to that necessary to overcome scheduling
22 * latency.
23 *
24 * - A Diffserv-aware priority queue, giving more priority to certain classes,
25 * up to a specified fraction of bandwidth. Above that bandwidth threshold,
26 * the priority is reduced to avoid starving other tins.
27 *
28 * - Each priority tin has a separate Flow Queue system, to isolate traffic
29 * flows from each other. This prevents a burst on one flow from increasing
30 * the delay to another. Flows are distributed to queues using a
31 * set-associative hash function.
32 *
33 * - Each queue is actively managed by Cobalt, which is a combination of the
34 * Codel and Blue AQM algorithms. This serves flows fairly, and signals
35 * congestion early via ECN (if available) and/or packet drops, to keep
36 * latency low. The codel parameters are auto-tuned based on the bandwidth
37 * setting, as is necessary at low bandwidths.
38 *
39 * The configuration parameters are kept deliberately simple for ease of use.
40 * Everything has sane defaults. Complete generality of configuration is *not*
41 * a goal.
42 *
43 * The priority queue operates according to a weighted DRR scheme, combined with
44 * a bandwidth tracker which reuses the shaper logic to detect which side of the
45 * bandwidth sharing threshold the tin is operating. This determines whether a
46 * priority-based weight (high) or a bandwidth-based weight (low) is used for
47 * that tin in the current pass.
48 *
49 * This qdisc was inspired by Eric Dumazet's fq_codel code, which he kindly
50 * granted us permission to leverage.
51 */
52
53#include <linux/module.h>
54#include <linux/types.h>
55#include <linux/kernel.h>
56#include <linux/jiffies.h>
57#include <linux/string.h>
58#include <linux/in.h>
59#include <linux/errno.h>
60#include <linux/init.h>
61#include <linux/skbuff.h>
62#include <linux/jhash.h>
63#include <linux/slab.h>
64#include <linux/vmalloc.h>
65#include <linux/reciprocal_div.h>
66#include <net/netlink.h>
67#include <linux/if_vlan.h>
68#include <net/pkt_sched.h>
69#include <net/pkt_cls.h>
70#include <net/tcp.h>
71#include <net/flow_dissector.h>
72
73#if IS_ENABLED(CONFIG_NF_CONNTRACK)
74#include <net/netfilter/nf_conntrack_core.h>
75#endif
76
77#define CAKE_SET_WAYS (8)
78#define CAKE_MAX_TINS (8)
79#define CAKE_QUEUES (1024)
80#define CAKE_FLOW_MASK 63
81#define CAKE_FLOW_NAT_FLAG 64
82
83/* struct cobalt_params - contains codel and blue parameters
84 * @interval: codel initial drop rate
85 * @target: maximum persistent sojourn time & blue update rate
86 * @mtu_time: serialisation delay of maximum-size packet
87 * @p_inc: increment of blue drop probability (0.32 fxp)
88 * @p_dec: decrement of blue drop probability (0.32 fxp)
89 */
90struct cobalt_params {
91 u64 interval;
92 u64 target;
93 u64 mtu_time;
94 u32 p_inc;
95 u32 p_dec;
96};
97
98/* struct cobalt_vars - contains codel and blue variables
99 * @count: codel dropping frequency
100 * @rec_inv_sqrt: reciprocal value of sqrt(count) >> 1
101 * @drop_next: time to drop next packet, or when we dropped last
102 * @blue_timer: Blue time to next drop
103 * @p_drop: BLUE drop probability (0.32 fxp)
104 * @dropping: set if in dropping state
105 * @ecn_marked: set if marked
106 */
107struct cobalt_vars {
108 u32 count;
109 u32 rec_inv_sqrt;
110 ktime_t drop_next;
111 ktime_t blue_timer;
112 u32 p_drop;
113 bool dropping;
114 bool ecn_marked;
115};
116
117enum {
118 CAKE_SET_NONE = 0,
119 CAKE_SET_SPARSE,
120 CAKE_SET_SPARSE_WAIT, /* counted in SPARSE, actually in BULK */
121 CAKE_SET_BULK,
122 CAKE_SET_DECAYING
123};
124
125struct cake_flow {
126 /* this stuff is all needed per-flow at dequeue time */
127 struct sk_buff *head;
128 struct sk_buff *tail;
129 struct list_head flowchain;
130 s32 deficit;
131 u32 dropped;
132 struct cobalt_vars cvars;
133 u16 srchost; /* index into cake_host table */
134 u16 dsthost;
135 u8 set;
136}; /* please try to keep this structure <= 64 bytes */
137
138struct cake_host {
139 u32 srchost_tag;
140 u32 dsthost_tag;
141 u16 srchost_bulk_flow_count;
142 u16 dsthost_bulk_flow_count;
143};
144
145struct cake_heap_entry {
146 u16 t:3, b:10;
147};
148
149struct cake_tin_data {
150 struct cake_flow flows[CAKE_QUEUES];
151 u32 backlogs[CAKE_QUEUES];
152 u32 tags[CAKE_QUEUES]; /* for set association */
153 u16 overflow_idx[CAKE_QUEUES];
154 struct cake_host hosts[CAKE_QUEUES]; /* for triple isolation */
155 u16 flow_quantum;
156
157 struct cobalt_params cparams;
158 u32 drop_overlimit;
159 u16 bulk_flow_count;
160 u16 sparse_flow_count;
161 u16 decaying_flow_count;
162 u16 unresponsive_flow_count;
163
164 u32 max_skblen;
165
166 struct list_head new_flows;
167 struct list_head old_flows;
168 struct list_head decaying_flows;
169
170 /* time_next = time_this + ((len * rate_ns) >> rate_shft) */
171 ktime_t time_next_packet;
172 u64 tin_rate_ns;
173 u64 tin_rate_bps;
174 u16 tin_rate_shft;
175
176 u16 tin_quantum_prio;
177 u16 tin_quantum_band;
178 s32 tin_deficit;
179 u32 tin_backlog;
180 u32 tin_dropped;
181 u32 tin_ecn_mark;
182
183 u32 packets;
184 u64 bytes;
185
186 u32 ack_drops;
187
188 /* moving averages */
189 u64 avge_delay;
190 u64 peak_delay;
191 u64 base_delay;
192
193 /* hash function stats */
194 u32 way_directs;
195 u32 way_hits;
196 u32 way_misses;
197 u32 way_collisions;
198}; /* number of tins is small, so size of this struct doesn't matter much */
199
200struct cake_sched_data {
201 struct tcf_proto __rcu *filter_list; /* optional external classifier */
202 struct tcf_block *block;
203 struct cake_tin_data *tins;
204
205 struct cake_heap_entry overflow_heap[CAKE_QUEUES * CAKE_MAX_TINS];
206 u16 overflow_timeout;
207
208 u16 tin_cnt;
209 u8 tin_mode;
210 u8 flow_mode;
211 u8 ack_filter;
212 u8 atm_mode;
213
214 u32 fwmark_mask;
215 u16 fwmark_shft;
216
217 /* time_next = time_this + ((len * rate_ns) >> rate_shft) */
218 u16 rate_shft;
219 ktime_t time_next_packet;
220 ktime_t failsafe_next_packet;
221 u64 rate_ns;
222 u64 rate_bps;
223 u16 rate_flags;
224 s16 rate_overhead;
225 u16 rate_mpu;
226 u64 interval;
227 u64 target;
228
229 /* resource tracking */
230 u32 buffer_used;
231 u32 buffer_max_used;
232 u32 buffer_limit;
233 u32 buffer_config_limit;
234
235 /* indices for dequeue */
236 u16 cur_tin;
237 u16 cur_flow;
238
239 struct qdisc_watchdog watchdog;
240 const u8 *tin_index;
241 const u8 *tin_order;
242
243 /* bandwidth capacity estimate */
244 ktime_t last_packet_time;
245 ktime_t avg_window_begin;
246 u64 avg_packet_interval;
247 u64 avg_window_bytes;
248 u64 avg_peak_bandwidth;
249 ktime_t last_reconfig_time;
250
251 /* packet length stats */
252 u32 avg_netoff;
253 u16 max_netlen;
254 u16 max_adjlen;
255 u16 min_netlen;
256 u16 min_adjlen;
257};
258
259enum {
260 CAKE_FLAG_OVERHEAD = BIT(0),
261 CAKE_FLAG_AUTORATE_INGRESS = BIT(1),
262 CAKE_FLAG_INGRESS = BIT(2),
263 CAKE_FLAG_WASH = BIT(3),
264 CAKE_FLAG_SPLIT_GSO = BIT(4)
265};
266
267/* COBALT operates the Codel and BLUE algorithms in parallel, in order to
268 * obtain the best features of each. Codel is excellent on flows which
269 * respond to congestion signals in a TCP-like way. BLUE is more effective on
270 * unresponsive flows.
271 */
272
273struct cobalt_skb_cb {
274 ktime_t enqueue_time;
275 u32 adjusted_len;
276};
277
278static u64 us_to_ns(u64 us)
279{
280 return us * NSEC_PER_USEC;
281}
282
283static struct cobalt_skb_cb *get_cobalt_cb(const struct sk_buff *skb)
284{
285 qdisc_cb_private_validate(skb, sizeof(struct cobalt_skb_cb));
286 return (struct cobalt_skb_cb *)qdisc_skb_cb(skb)->data;
287}
288
289static ktime_t cobalt_get_enqueue_time(const struct sk_buff *skb)
290{
291 return get_cobalt_cb(skb)->enqueue_time;
292}
293
294static void cobalt_set_enqueue_time(struct sk_buff *skb,
295 ktime_t now)
296{
297 get_cobalt_cb(skb)->enqueue_time = now;
298}
299
300static u16 quantum_div[CAKE_QUEUES + 1] = {0};
301
302/* Diffserv lookup tables */
303
304static const u8 precedence[] = {
305 0, 0, 0, 0, 0, 0, 0, 0,
306 1, 1, 1, 1, 1, 1, 1, 1,
307 2, 2, 2, 2, 2, 2, 2, 2,
308 3, 3, 3, 3, 3, 3, 3, 3,
309 4, 4, 4, 4, 4, 4, 4, 4,
310 5, 5, 5, 5, 5, 5, 5, 5,
311 6, 6, 6, 6, 6, 6, 6, 6,
312 7, 7, 7, 7, 7, 7, 7, 7,
313};
314
315static const u8 diffserv8[] = {
316 2, 5, 1, 2, 4, 2, 2, 2,
317 0, 2, 1, 2, 1, 2, 1, 2,
318 5, 2, 4, 2, 4, 2, 4, 2,
319 3, 2, 3, 2, 3, 2, 3, 2,
320 6, 2, 3, 2, 3, 2, 3, 2,
321 6, 2, 2, 2, 6, 2, 6, 2,
322 7, 2, 2, 2, 2, 2, 2, 2,
323 7, 2, 2, 2, 2, 2, 2, 2,
324};
325
326static const u8 diffserv4[] = {
327 0, 2, 0, 0, 2, 0, 0, 0,
328 1, 0, 0, 0, 0, 0, 0, 0,
329 2, 0, 2, 0, 2, 0, 2, 0,
330 2, 0, 2, 0, 2, 0, 2, 0,
331 3, 0, 2, 0, 2, 0, 2, 0,
332 3, 0, 0, 0, 3, 0, 3, 0,
333 3, 0, 0, 0, 0, 0, 0, 0,
334 3, 0, 0, 0, 0, 0, 0, 0,
335};
336
337static const u8 diffserv3[] = {
338 0, 0, 0, 0, 2, 0, 0, 0,
339 1, 0, 0, 0, 0, 0, 0, 0,
340 0, 0, 0, 0, 0, 0, 0, 0,
341 0, 0, 0, 0, 0, 0, 0, 0,
342 0, 0, 0, 0, 0, 0, 0, 0,
343 0, 0, 0, 0, 2, 0, 2, 0,
344 2, 0, 0, 0, 0, 0, 0, 0,
345 2, 0, 0, 0, 0, 0, 0, 0,
346};
347
348static const u8 besteffort[] = {
349 0, 0, 0, 0, 0, 0, 0, 0,
350 0, 0, 0, 0, 0, 0, 0, 0,
351 0, 0, 0, 0, 0, 0, 0, 0,
352 0, 0, 0, 0, 0, 0, 0, 0,
353 0, 0, 0, 0, 0, 0, 0, 0,
354 0, 0, 0, 0, 0, 0, 0, 0,
355 0, 0, 0, 0, 0, 0, 0, 0,
356 0, 0, 0, 0, 0, 0, 0, 0,
357};
358
359/* tin priority order for stats dumping */
360
361static const u8 normal_order[] = {0, 1, 2, 3, 4, 5, 6, 7};
362static const u8 bulk_order[] = {1, 0, 2, 3};
363
364#define REC_INV_SQRT_CACHE (16)
365static u32 cobalt_rec_inv_sqrt_cache[REC_INV_SQRT_CACHE] = {0};
366
367/* http://en.wikipedia.org/wiki/Methods_of_computing_square_roots
368 * new_invsqrt = (invsqrt / 2) * (3 - count * invsqrt^2)
369 *
370 * Here, invsqrt is a fixed point number (< 1.0), 32bit mantissa, aka Q0.32
371 */
372
373static void cobalt_newton_step(struct cobalt_vars *vars)
374{
375 u32 invsqrt, invsqrt2;
376 u64 val;
377
378 invsqrt = vars->rec_inv_sqrt;
379 invsqrt2 = ((u64)invsqrt * invsqrt) >> 32;
380 val = (3LL << 32) - ((u64)vars->count * invsqrt2);
381
382 val >>= 2; /* avoid overflow in following multiply */
383 val = (val * invsqrt) >> (32 - 2 + 1);
384
385 vars->rec_inv_sqrt = val;
386}
387
388static void cobalt_invsqrt(struct cobalt_vars *vars)
389{
390 if (vars->count < REC_INV_SQRT_CACHE)
391 vars->rec_inv_sqrt = cobalt_rec_inv_sqrt_cache[vars->count];
392 else
393 cobalt_newton_step(vars);
394}
395
396/* There is a big difference in timing between the accurate values placed in
397 * the cache and the approximations given by a single Newton step for small
398 * count values, particularly when stepping from count 1 to 2 or vice versa.
399 * Above 16, a single Newton step gives sufficient accuracy in either
400 * direction, given the precision stored.
401 *
402 * The magnitude of the error when stepping up to count 2 is such as to give
403 * the value that *should* have been produced at count 4.
404 */
405
406static void cobalt_cache_init(void)
407{
408 struct cobalt_vars v;
409
410 memset(&v, 0, sizeof(v));
411 v.rec_inv_sqrt = ~0U;
412 cobalt_rec_inv_sqrt_cache[0] = v.rec_inv_sqrt;
413
414 for (v.count = 1; v.count < REC_INV_SQRT_CACHE; v.count++) {
415 cobalt_newton_step(&v);
416 cobalt_newton_step(&v);
417 cobalt_newton_step(&v);
418 cobalt_newton_step(&v);
419
420 cobalt_rec_inv_sqrt_cache[v.count] = v.rec_inv_sqrt;
421 }
422}
423
424static void cobalt_vars_init(struct cobalt_vars *vars)
425{
426 memset(vars, 0, sizeof(*vars));
427
428 if (!cobalt_rec_inv_sqrt_cache[0]) {
429 cobalt_cache_init();
430 cobalt_rec_inv_sqrt_cache[0] = ~0;
431 }
432}
433
434/* CoDel control_law is t + interval/sqrt(count)
435 * We maintain in rec_inv_sqrt the reciprocal value of sqrt(count) to avoid
436 * both sqrt() and divide operation.
437 */
438static ktime_t cobalt_control(ktime_t t,
439 u64 interval,
440 u32 rec_inv_sqrt)
441{
442 return ktime_add_ns(t, reciprocal_scale(interval,
443 rec_inv_sqrt));
444}
445
446/* Call this when a packet had to be dropped due to queue overflow. Returns
447 * true if the BLUE state was quiescent before but active after this call.
448 */
449static bool cobalt_queue_full(struct cobalt_vars *vars,
450 struct cobalt_params *p,
451 ktime_t now)
452{
453 bool up = false;
454
455 if (ktime_to_ns(ktime_sub(now, vars->blue_timer)) > p->target) {
456 up = !vars->p_drop;
457 vars->p_drop += p->p_inc;
458 if (vars->p_drop < p->p_inc)
459 vars->p_drop = ~0;
460 vars->blue_timer = now;
461 }
462 vars->dropping = true;
463 vars->drop_next = now;
464 if (!vars->count)
465 vars->count = 1;
466
467 return up;
468}
469
470/* Call this when the queue was serviced but turned out to be empty. Returns
471 * true if the BLUE state was active before but quiescent after this call.
472 */
473static bool cobalt_queue_empty(struct cobalt_vars *vars,
474 struct cobalt_params *p,
475 ktime_t now)
476{
477 bool down = false;
478
479 if (vars->p_drop &&
480 ktime_to_ns(ktime_sub(now, vars->blue_timer)) > p->target) {
481 if (vars->p_drop < p->p_dec)
482 vars->p_drop = 0;
483 else
484 vars->p_drop -= p->p_dec;
485 vars->blue_timer = now;
486 down = !vars->p_drop;
487 }
488 vars->dropping = false;
489
490 if (vars->count && ktime_to_ns(ktime_sub(now, vars->drop_next)) >= 0) {
491 vars->count--;
492 cobalt_invsqrt(vars);
493 vars->drop_next = cobalt_control(vars->drop_next,
494 p->interval,
495 vars->rec_inv_sqrt);
496 }
497
498 return down;
499}
500
501/* Call this with a freshly dequeued packet for possible congestion marking.
502 * Returns true as an instruction to drop the packet, false for delivery.
503 */
504static bool cobalt_should_drop(struct cobalt_vars *vars,
505 struct cobalt_params *p,
506 ktime_t now,
507 struct sk_buff *skb,
508 u32 bulk_flows)
509{
510 bool next_due, over_target, drop = false;
511 ktime_t schedule;
512 u64 sojourn;
513
514/* The 'schedule' variable records, in its sign, whether 'now' is before or
515 * after 'drop_next'. This allows 'drop_next' to be updated before the next
516 * scheduling decision is actually branched, without destroying that
517 * information. Similarly, the first 'schedule' value calculated is preserved
518 * in the boolean 'next_due'.
519 *
520 * As for 'drop_next', we take advantage of the fact that 'interval' is both
521 * the delay between first exceeding 'target' and the first signalling event,
522 * *and* the scaling factor for the signalling frequency. It's therefore very
523 * natural to use a single mechanism for both purposes, and eliminates a
524 * significant amount of reference Codel's spaghetti code. To help with this,
525 * both the '0' and '1' entries in the invsqrt cache are 0xFFFFFFFF, as close
526 * as possible to 1.0 in fixed-point.
527 */
528
529 sojourn = ktime_to_ns(ktime_sub(now, cobalt_get_enqueue_time(skb)));
530 schedule = ktime_sub(now, vars->drop_next);
531 over_target = sojourn > p->target &&
532 sojourn > p->mtu_time * bulk_flows * 2 &&
533 sojourn > p->mtu_time * 4;
534 next_due = vars->count && ktime_to_ns(schedule) >= 0;
535
536 vars->ecn_marked = false;
537
538 if (over_target) {
539 if (!vars->dropping) {
540 vars->dropping = true;
541 vars->drop_next = cobalt_control(now,
542 p->interval,
543 vars->rec_inv_sqrt);
544 }
545 if (!vars->count)
546 vars->count = 1;
547 } else if (vars->dropping) {
548 vars->dropping = false;
549 }
550
551 if (next_due && vars->dropping) {
552 /* Use ECN mark if possible, otherwise drop */
553 drop = !(vars->ecn_marked = INET_ECN_set_ce(skb));
554
555 vars->count++;
556 if (!vars->count)
557 vars->count--;
558 cobalt_invsqrt(vars);
559 vars->drop_next = cobalt_control(vars->drop_next,
560 p->interval,
561 vars->rec_inv_sqrt);
562 schedule = ktime_sub(now, vars->drop_next);
563 } else {
564 while (next_due) {
565 vars->count--;
566 cobalt_invsqrt(vars);
567 vars->drop_next = cobalt_control(vars->drop_next,
568 p->interval,
569 vars->rec_inv_sqrt);
570 schedule = ktime_sub(now, vars->drop_next);
571 next_due = vars->count && ktime_to_ns(schedule) >= 0;
572 }
573 }
574
575 /* Simple BLUE implementation. Lack of ECN is deliberate. */
576 if (vars->p_drop)
577 drop |= (prandom_u32() < vars->p_drop);
578
579 /* Overload the drop_next field as an activity timeout */
580 if (!vars->count)
581 vars->drop_next = ktime_add_ns(now, p->interval);
582 else if (ktime_to_ns(schedule) > 0 && !drop)
583 vars->drop_next = now;
584
585 return drop;
586}
587
588static void cake_update_flowkeys(struct flow_keys *keys,
589 const struct sk_buff *skb)
590{
591#if IS_ENABLED(CONFIG_NF_CONNTRACK)
592 struct nf_conntrack_tuple tuple = {};
593 bool rev = !skb->_nfct;
594
595 if (tc_skb_protocol(skb) != htons(ETH_P_IP))
596 return;
597
598 if (!nf_ct_get_tuple_skb(&tuple, skb))
599 return;
600
601 keys->addrs.v4addrs.src = rev ? tuple.dst.u3.ip : tuple.src.u3.ip;
602 keys->addrs.v4addrs.dst = rev ? tuple.src.u3.ip : tuple.dst.u3.ip;
603
604 if (keys->ports.ports) {
605 keys->ports.src = rev ? tuple.dst.u.all : tuple.src.u.all;
606 keys->ports.dst = rev ? tuple.src.u.all : tuple.dst.u.all;
607 }
608#endif
609}
610
611/* Cake has several subtle multiple bit settings. In these cases you
612 * would be matching triple isolate mode as well.
613 */
614
615static bool cake_dsrc(int flow_mode)
616{
617 return (flow_mode & CAKE_FLOW_DUAL_SRC) == CAKE_FLOW_DUAL_SRC;
618}
619
620static bool cake_ddst(int flow_mode)
621{
622 return (flow_mode & CAKE_FLOW_DUAL_DST) == CAKE_FLOW_DUAL_DST;
623}
624
625static u32 cake_hash(struct cake_tin_data *q, const struct sk_buff *skb,
626 int flow_mode, u16 flow_override, u16 host_override)
627{
628 u32 flow_hash = 0, srchost_hash = 0, dsthost_hash = 0;
629 u16 reduced_hash, srchost_idx, dsthost_idx;
630 struct flow_keys keys, host_keys;
631
632 if (unlikely(flow_mode == CAKE_FLOW_NONE))
633 return 0;
634
635 /* If both overrides are set we can skip packet dissection entirely */
636 if ((flow_override || !(flow_mode & CAKE_FLOW_FLOWS)) &&
637 (host_override || !(flow_mode & CAKE_FLOW_HOSTS)))
638 goto skip_hash;
639
640 skb_flow_dissect_flow_keys(skb, &keys,
641 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
642
643 if (flow_mode & CAKE_FLOW_NAT_FLAG)
644 cake_update_flowkeys(&keys, skb);
645
646 /* flow_hash_from_keys() sorts the addresses by value, so we have
647 * to preserve their order in a separate data structure to treat
648 * src and dst host addresses as independently selectable.
649 */
650 host_keys = keys;
651 host_keys.ports.ports = 0;
652 host_keys.basic.ip_proto = 0;
653 host_keys.keyid.keyid = 0;
654 host_keys.tags.flow_label = 0;
655
656 switch (host_keys.control.addr_type) {
657 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
658 host_keys.addrs.v4addrs.src = 0;
659 dsthost_hash = flow_hash_from_keys(&host_keys);
660 host_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
661 host_keys.addrs.v4addrs.dst = 0;
662 srchost_hash = flow_hash_from_keys(&host_keys);
663 break;
664
665 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
666 memset(&host_keys.addrs.v6addrs.src, 0,
667 sizeof(host_keys.addrs.v6addrs.src));
668 dsthost_hash = flow_hash_from_keys(&host_keys);
669 host_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
670 memset(&host_keys.addrs.v6addrs.dst, 0,
671 sizeof(host_keys.addrs.v6addrs.dst));
672 srchost_hash = flow_hash_from_keys(&host_keys);
673 break;
674
675 default:
676 dsthost_hash = 0;
677 srchost_hash = 0;
678 }
679
680 /* This *must* be after the above switch, since as a
681 * side-effect it sorts the src and dst addresses.
682 */
683 if (flow_mode & CAKE_FLOW_FLOWS)
684 flow_hash = flow_hash_from_keys(&keys);
685
686skip_hash:
687 if (flow_override)
688 flow_hash = flow_override - 1;
689 if (host_override) {
690 dsthost_hash = host_override - 1;
691 srchost_hash = host_override - 1;
692 }
693
694 if (!(flow_mode & CAKE_FLOW_FLOWS)) {
695 if (flow_mode & CAKE_FLOW_SRC_IP)
696 flow_hash ^= srchost_hash;
697
698 if (flow_mode & CAKE_FLOW_DST_IP)
699 flow_hash ^= dsthost_hash;
700 }
701
702 reduced_hash = flow_hash % CAKE_QUEUES;
703
704 /* set-associative hashing */
705 /* fast path if no hash collision (direct lookup succeeds) */
706 if (likely(q->tags[reduced_hash] == flow_hash &&
707 q->flows[reduced_hash].set)) {
708 q->way_directs++;
709 } else {
710 u32 inner_hash = reduced_hash % CAKE_SET_WAYS;
711 u32 outer_hash = reduced_hash - inner_hash;
712 bool allocate_src = false;
713 bool allocate_dst = false;
714 u32 i, k;
715
716 /* check if any active queue in the set is reserved for
717 * this flow.
718 */
719 for (i = 0, k = inner_hash; i < CAKE_SET_WAYS;
720 i++, k = (k + 1) % CAKE_SET_WAYS) {
721 if (q->tags[outer_hash + k] == flow_hash) {
722 if (i)
723 q->way_hits++;
724
725 if (!q->flows[outer_hash + k].set) {
726 /* need to increment host refcnts */
727 allocate_src = cake_dsrc(flow_mode);
728 allocate_dst = cake_ddst(flow_mode);
729 }
730
731 goto found;
732 }
733 }
734
735 /* no queue is reserved for this flow, look for an
736 * empty one.
737 */
738 for (i = 0; i < CAKE_SET_WAYS;
739 i++, k = (k + 1) % CAKE_SET_WAYS) {
740 if (!q->flows[outer_hash + k].set) {
741 q->way_misses++;
742 allocate_src = cake_dsrc(flow_mode);
743 allocate_dst = cake_ddst(flow_mode);
744 goto found;
745 }
746 }
747
748 /* With no empty queues, default to the original
749 * queue, accept the collision, update the host tags.
750 */
751 q->way_collisions++;
752 if (q->flows[outer_hash + k].set == CAKE_SET_BULK) {
753 q->hosts[q->flows[reduced_hash].srchost].srchost_bulk_flow_count--;
754 q->hosts[q->flows[reduced_hash].dsthost].dsthost_bulk_flow_count--;
755 }
756 allocate_src = cake_dsrc(flow_mode);
757 allocate_dst = cake_ddst(flow_mode);
758found:
759 /* reserve queue for future packets in same flow */
760 reduced_hash = outer_hash + k;
761 q->tags[reduced_hash] = flow_hash;
762
763 if (allocate_src) {
764 srchost_idx = srchost_hash % CAKE_QUEUES;
765 inner_hash = srchost_idx % CAKE_SET_WAYS;
766 outer_hash = srchost_idx - inner_hash;
767 for (i = 0, k = inner_hash; i < CAKE_SET_WAYS;
768 i++, k = (k + 1) % CAKE_SET_WAYS) {
769 if (q->hosts[outer_hash + k].srchost_tag ==
770 srchost_hash)
771 goto found_src;
772 }
773 for (i = 0; i < CAKE_SET_WAYS;
774 i++, k = (k + 1) % CAKE_SET_WAYS) {
775 if (!q->hosts[outer_hash + k].srchost_bulk_flow_count)
776 break;
777 }
778 q->hosts[outer_hash + k].srchost_tag = srchost_hash;
779found_src:
780 srchost_idx = outer_hash + k;
781 if (q->flows[reduced_hash].set == CAKE_SET_BULK)
782 q->hosts[srchost_idx].srchost_bulk_flow_count++;
783 q->flows[reduced_hash].srchost = srchost_idx;
784 }
785
786 if (allocate_dst) {
787 dsthost_idx = dsthost_hash % CAKE_QUEUES;
788 inner_hash = dsthost_idx % CAKE_SET_WAYS;
789 outer_hash = dsthost_idx - inner_hash;
790 for (i = 0, k = inner_hash; i < CAKE_SET_WAYS;
791 i++, k = (k + 1) % CAKE_SET_WAYS) {
792 if (q->hosts[outer_hash + k].dsthost_tag ==
793 dsthost_hash)
794 goto found_dst;
795 }
796 for (i = 0; i < CAKE_SET_WAYS;
797 i++, k = (k + 1) % CAKE_SET_WAYS) {
798 if (!q->hosts[outer_hash + k].dsthost_bulk_flow_count)
799 break;
800 }
801 q->hosts[outer_hash + k].dsthost_tag = dsthost_hash;
802found_dst:
803 dsthost_idx = outer_hash + k;
804 if (q->flows[reduced_hash].set == CAKE_SET_BULK)
805 q->hosts[dsthost_idx].dsthost_bulk_flow_count++;
806 q->flows[reduced_hash].dsthost = dsthost_idx;
807 }
808 }
809
810 return reduced_hash;
811}
812
813/* helper functions : might be changed when/if skb use a standard list_head */
814/* remove one skb from head of slot queue */
815
816static struct sk_buff *dequeue_head(struct cake_flow *flow)
817{
818 struct sk_buff *skb = flow->head;
819
820 if (skb) {
821 flow->head = skb->next;
822 skb_mark_not_on_list(skb);
823 }
824
825 return skb;
826}
827
828/* add skb to flow queue (tail add) */
829
830static void flow_queue_add(struct cake_flow *flow, struct sk_buff *skb)
831{
832 if (!flow->head)
833 flow->head = skb;
834 else
835 flow->tail->next = skb;
836 flow->tail = skb;
837 skb->next = NULL;
838}
839
840static struct iphdr *cake_get_iphdr(const struct sk_buff *skb,
841 struct ipv6hdr *buf)
842{
843 unsigned int offset = skb_network_offset(skb);
844 struct iphdr *iph;
845
846 iph = skb_header_pointer(skb, offset, sizeof(struct iphdr), buf);
847
848 if (!iph)
849 return NULL;
850
851 if (iph->version == 4 && iph->protocol == IPPROTO_IPV6)
852 return skb_header_pointer(skb, offset + iph->ihl * 4,
853 sizeof(struct ipv6hdr), buf);
854
855 else if (iph->version == 4)
856 return iph;
857
858 else if (iph->version == 6)
859 return skb_header_pointer(skb, offset, sizeof(struct ipv6hdr),
860 buf);
861
862 return NULL;
863}
864
865static struct tcphdr *cake_get_tcphdr(const struct sk_buff *skb,
866 void *buf, unsigned int bufsize)
867{
868 unsigned int offset = skb_network_offset(skb);
869 const struct ipv6hdr *ipv6h;
870 const struct tcphdr *tcph;
871 const struct iphdr *iph;
872 struct ipv6hdr _ipv6h;
873 struct tcphdr _tcph;
874
875 ipv6h = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
876
877 if (!ipv6h)
878 return NULL;
879
880 if (ipv6h->version == 4) {
881 iph = (struct iphdr *)ipv6h;
882 offset += iph->ihl * 4;
883
884 /* special-case 6in4 tunnelling, as that is a common way to get
885 * v6 connectivity in the home
886 */
887 if (iph->protocol == IPPROTO_IPV6) {
888 ipv6h = skb_header_pointer(skb, offset,
889 sizeof(_ipv6h), &_ipv6h);
890
891 if (!ipv6h || ipv6h->nexthdr != IPPROTO_TCP)
892 return NULL;
893
894 offset += sizeof(struct ipv6hdr);
895
896 } else if (iph->protocol != IPPROTO_TCP) {
897 return NULL;
898 }
899
900 } else if (ipv6h->version == 6) {
901 if (ipv6h->nexthdr != IPPROTO_TCP)
902 return NULL;
903
904 offset += sizeof(struct ipv6hdr);
905 } else {
906 return NULL;
907 }
908
909 tcph = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
910 if (!tcph)
911 return NULL;
912
913 return skb_header_pointer(skb, offset,
914 min(__tcp_hdrlen(tcph), bufsize), buf);
915}
916
917static const void *cake_get_tcpopt(const struct tcphdr *tcph,
918 int code, int *oplen)
919{
920 /* inspired by tcp_parse_options in tcp_input.c */
921 int length = __tcp_hdrlen(tcph) - sizeof(struct tcphdr);
922 const u8 *ptr = (const u8 *)(tcph + 1);
923
924 while (length > 0) {
925 int opcode = *ptr++;
926 int opsize;
927
928 if (opcode == TCPOPT_EOL)
929 break;
930 if (opcode == TCPOPT_NOP) {
931 length--;
932 continue;
933 }
934 opsize = *ptr++;
935 if (opsize < 2 || opsize > length)
936 break;
937
938 if (opcode == code) {
939 *oplen = opsize;
940 return ptr;
941 }
942
943 ptr += opsize - 2;
944 length -= opsize;
945 }
946
947 return NULL;
948}
949
950/* Compare two SACK sequences. A sequence is considered greater if it SACKs more
951 * bytes than the other. In the case where both sequences ACKs bytes that the
952 * other doesn't, A is considered greater. DSACKs in A also makes A be
953 * considered greater.
954 *
955 * @return -1, 0 or 1 as normal compare functions
956 */
957static int cake_tcph_sack_compare(const struct tcphdr *tcph_a,
958 const struct tcphdr *tcph_b)
959{
960 const struct tcp_sack_block_wire *sack_a, *sack_b;
961 u32 ack_seq_a = ntohl(tcph_a->ack_seq);
962 u32 bytes_a = 0, bytes_b = 0;
963 int oplen_a, oplen_b;
964 bool first = true;
965
966 sack_a = cake_get_tcpopt(tcph_a, TCPOPT_SACK, &oplen_a);
967 sack_b = cake_get_tcpopt(tcph_b, TCPOPT_SACK, &oplen_b);
968
969 /* pointers point to option contents */
970 oplen_a -= TCPOLEN_SACK_BASE;
971 oplen_b -= TCPOLEN_SACK_BASE;
972
973 if (sack_a && oplen_a >= sizeof(*sack_a) &&
974 (!sack_b || oplen_b < sizeof(*sack_b)))
975 return -1;
976 else if (sack_b && oplen_b >= sizeof(*sack_b) &&
977 (!sack_a || oplen_a < sizeof(*sack_a)))
978 return 1;
979 else if ((!sack_a || oplen_a < sizeof(*sack_a)) &&
980 (!sack_b || oplen_b < sizeof(*sack_b)))
981 return 0;
982
983 while (oplen_a >= sizeof(*sack_a)) {
984 const struct tcp_sack_block_wire *sack_tmp = sack_b;
985 u32 start_a = get_unaligned_be32(&sack_a->start_seq);
986 u32 end_a = get_unaligned_be32(&sack_a->end_seq);
987 int oplen_tmp = oplen_b;
988 bool found = false;
989
990 /* DSACK; always considered greater to prevent dropping */
991 if (before(start_a, ack_seq_a))
992 return -1;
993
994 bytes_a += end_a - start_a;
995
996 while (oplen_tmp >= sizeof(*sack_tmp)) {
997 u32 start_b = get_unaligned_be32(&sack_tmp->start_seq);
998 u32 end_b = get_unaligned_be32(&sack_tmp->end_seq);
999
1000 /* first time through we count the total size */
1001 if (first)
1002 bytes_b += end_b - start_b;
1003
1004 if (!after(start_b, start_a) && !before(end_b, end_a)) {
1005 found = true;
1006 if (!first)
1007 break;
1008 }
1009 oplen_tmp -= sizeof(*sack_tmp);
1010 sack_tmp++;
1011 }
1012
1013 if (!found)
1014 return -1;
1015
1016 oplen_a -= sizeof(*sack_a);
1017 sack_a++;
1018 first = false;
1019 }
1020
1021 /* If we made it this far, all ranges SACKed by A are covered by B, so
1022 * either the SACKs are equal, or B SACKs more bytes.
1023 */
1024 return bytes_b > bytes_a ? 1 : 0;
1025}
1026
1027static void cake_tcph_get_tstamp(const struct tcphdr *tcph,
1028 u32 *tsval, u32 *tsecr)
1029{
1030 const u8 *ptr;
1031 int opsize;
1032
1033 ptr = cake_get_tcpopt(tcph, TCPOPT_TIMESTAMP, &opsize);
1034
1035 if (ptr && opsize == TCPOLEN_TIMESTAMP) {
1036 *tsval = get_unaligned_be32(ptr);
1037 *tsecr = get_unaligned_be32(ptr + 4);
1038 }
1039}
1040
1041static bool cake_tcph_may_drop(const struct tcphdr *tcph,
1042 u32 tstamp_new, u32 tsecr_new)
1043{
1044 /* inspired by tcp_parse_options in tcp_input.c */
1045 int length = __tcp_hdrlen(tcph) - sizeof(struct tcphdr);
1046 const u8 *ptr = (const u8 *)(tcph + 1);
1047 u32 tstamp, tsecr;
1048
1049 /* 3 reserved flags must be unset to avoid future breakage
1050 * ACK must be set
1051 * ECE/CWR are handled separately
1052 * All other flags URG/PSH/RST/SYN/FIN must be unset
1053 * 0x0FFF0000 = all TCP flags (confirm ACK=1, others zero)
1054 * 0x00C00000 = CWR/ECE (handled separately)
1055 * 0x0F3F0000 = 0x0FFF0000 & ~0x00C00000
1056 */
1057 if (((tcp_flag_word(tcph) &
1058 cpu_to_be32(0x0F3F0000)) != TCP_FLAG_ACK))
1059 return false;
1060
1061 while (length > 0) {
1062 int opcode = *ptr++;
1063 int opsize;
1064
1065 if (opcode == TCPOPT_EOL)
1066 break;
1067 if (opcode == TCPOPT_NOP) {
1068 length--;
1069 continue;
1070 }
1071 opsize = *ptr++;
1072 if (opsize < 2 || opsize > length)
1073 break;
1074
1075 switch (opcode) {
1076 case TCPOPT_MD5SIG: /* doesn't influence state */
1077 break;
1078
1079 case TCPOPT_SACK: /* stricter checking performed later */
1080 if (opsize % 8 != 2)
1081 return false;
1082 break;
1083
1084 case TCPOPT_TIMESTAMP:
1085 /* only drop timestamps lower than new */
1086 if (opsize != TCPOLEN_TIMESTAMP)
1087 return false;
1088 tstamp = get_unaligned_be32(ptr);
1089 tsecr = get_unaligned_be32(ptr + 4);
1090 if (after(tstamp, tstamp_new) ||
1091 after(tsecr, tsecr_new))
1092 return false;
1093 break;
1094
1095 case TCPOPT_MSS: /* these should only be set on SYN */
1096 case TCPOPT_WINDOW:
1097 case TCPOPT_SACK_PERM:
1098 case TCPOPT_FASTOPEN:
1099 case TCPOPT_EXP:
1100 default: /* don't drop if any unknown options are present */
1101 return false;
1102 }
1103
1104 ptr += opsize - 2;
1105 length -= opsize;
1106 }
1107
1108 return true;
1109}
1110
1111static struct sk_buff *cake_ack_filter(struct cake_sched_data *q,
1112 struct cake_flow *flow)
1113{
1114 bool aggressive = q->ack_filter == CAKE_ACK_AGGRESSIVE;
1115 struct sk_buff *elig_ack = NULL, *elig_ack_prev = NULL;
1116 struct sk_buff *skb_check, *skb_prev = NULL;
1117 const struct ipv6hdr *ipv6h, *ipv6h_check;
1118 unsigned char _tcph[64], _tcph_check[64];
1119 const struct tcphdr *tcph, *tcph_check;
1120 const struct iphdr *iph, *iph_check;
1121 struct ipv6hdr _iph, _iph_check;
1122 const struct sk_buff *skb;
1123 int seglen, num_found = 0;
1124 u32 tstamp = 0, tsecr = 0;
1125 __be32 elig_flags = 0;
1126 int sack_comp;
1127
1128 /* no other possible ACKs to filter */
1129 if (flow->head == flow->tail)
1130 return NULL;
1131
1132 skb = flow->tail;
1133 tcph = cake_get_tcphdr(skb, _tcph, sizeof(_tcph));
1134 iph = cake_get_iphdr(skb, &_iph);
1135 if (!tcph)
1136 return NULL;
1137
1138 cake_tcph_get_tstamp(tcph, &tstamp, &tsecr);
1139
1140 /* the 'triggering' packet need only have the ACK flag set.
1141 * also check that SYN is not set, as there won't be any previous ACKs.
1142 */
1143 if ((tcp_flag_word(tcph) &
1144 (TCP_FLAG_ACK | TCP_FLAG_SYN)) != TCP_FLAG_ACK)
1145 return NULL;
1146
1147 /* the 'triggering' ACK is at the tail of the queue, we have already
1148 * returned if it is the only packet in the flow. loop through the rest
1149 * of the queue looking for pure ACKs with the same 5-tuple as the
1150 * triggering one.
1151 */
1152 for (skb_check = flow->head;
1153 skb_check && skb_check != skb;
1154 skb_prev = skb_check, skb_check = skb_check->next) {
1155 iph_check = cake_get_iphdr(skb_check, &_iph_check);
1156 tcph_check = cake_get_tcphdr(skb_check, &_tcph_check,
1157 sizeof(_tcph_check));
1158
1159 /* only TCP packets with matching 5-tuple are eligible, and only
1160 * drop safe headers
1161 */
1162 if (!tcph_check || iph->version != iph_check->version ||
1163 tcph_check->source != tcph->source ||
1164 tcph_check->dest != tcph->dest)
1165 continue;
1166
1167 if (iph_check->version == 4) {
1168 if (iph_check->saddr != iph->saddr ||
1169 iph_check->daddr != iph->daddr)
1170 continue;
1171
1172 seglen = ntohs(iph_check->tot_len) -
1173 (4 * iph_check->ihl);
1174 } else if (iph_check->version == 6) {
1175 ipv6h = (struct ipv6hdr *)iph;
1176 ipv6h_check = (struct ipv6hdr *)iph_check;
1177
1178 if (ipv6_addr_cmp(&ipv6h_check->saddr, &ipv6h->saddr) ||
1179 ipv6_addr_cmp(&ipv6h_check->daddr, &ipv6h->daddr))
1180 continue;
1181
1182 seglen = ntohs(ipv6h_check->payload_len);
1183 } else {
1184 WARN_ON(1); /* shouldn't happen */
1185 continue;
1186 }
1187
1188 /* If the ECE/CWR flags changed from the previous eligible
1189 * packet in the same flow, we should no longer be dropping that
1190 * previous packet as this would lose information.
1191 */
1192 if (elig_ack && (tcp_flag_word(tcph_check) &
1193 (TCP_FLAG_ECE | TCP_FLAG_CWR)) != elig_flags) {
1194 elig_ack = NULL;
1195 elig_ack_prev = NULL;
1196 num_found--;
1197 }
1198
1199 /* Check TCP options and flags, don't drop ACKs with segment
1200 * data, and don't drop ACKs with a higher cumulative ACK
1201 * counter than the triggering packet. Check ACK seqno here to
1202 * avoid parsing SACK options of packets we are going to exclude
1203 * anyway.
1204 */
1205 if (!cake_tcph_may_drop(tcph_check, tstamp, tsecr) ||
1206 (seglen - __tcp_hdrlen(tcph_check)) != 0 ||
1207 after(ntohl(tcph_check->ack_seq), ntohl(tcph->ack_seq)))
1208 continue;
1209
1210 /* Check SACK options. The triggering packet must SACK more data
1211 * than the ACK under consideration, or SACK the same range but
1212 * have a larger cumulative ACK counter. The latter is a
1213 * pathological case, but is contained in the following check
1214 * anyway, just to be safe.
1215 */
1216 sack_comp = cake_tcph_sack_compare(tcph_check, tcph);
1217
1218 if (sack_comp < 0 ||
1219 (ntohl(tcph_check->ack_seq) == ntohl(tcph->ack_seq) &&
1220 sack_comp == 0))
1221 continue;
1222
1223 /* At this point we have found an eligible pure ACK to drop; if
1224 * we are in aggressive mode, we are done. Otherwise, keep
1225 * searching unless this is the second eligible ACK we
1226 * found.
1227 *
1228 * Since we want to drop ACK closest to the head of the queue,
1229 * save the first eligible ACK we find, even if we need to loop
1230 * again.
1231 */
1232 if (!elig_ack) {
1233 elig_ack = skb_check;
1234 elig_ack_prev = skb_prev;
1235 elig_flags = (tcp_flag_word(tcph_check)
1236 & (TCP_FLAG_ECE | TCP_FLAG_CWR));
1237 }
1238
1239 if (num_found++ > 0)
1240 goto found;
1241 }
1242
1243 /* We made it through the queue without finding two eligible ACKs . If
1244 * we found a single eligible ACK we can drop it in aggressive mode if
1245 * we can guarantee that this does not interfere with ECN flag
1246 * information. We ensure this by dropping it only if the enqueued
1247 * packet is consecutive with the eligible ACK, and their flags match.
1248 */
1249 if (elig_ack && aggressive && elig_ack->next == skb &&
1250 (elig_flags == (tcp_flag_word(tcph) &
1251 (TCP_FLAG_ECE | TCP_FLAG_CWR))))
1252 goto found;
1253
1254 return NULL;
1255
1256found:
1257 if (elig_ack_prev)
1258 elig_ack_prev->next = elig_ack->next;
1259 else
1260 flow->head = elig_ack->next;
1261
1262 skb_mark_not_on_list(elig_ack);
1263
1264 return elig_ack;
1265}
1266
1267static u64 cake_ewma(u64 avg, u64 sample, u32 shift)
1268{
1269 avg -= avg >> shift;
1270 avg += sample >> shift;
1271 return avg;
1272}
1273
1274static u32 cake_calc_overhead(struct cake_sched_data *q, u32 len, u32 off)
1275{
1276 if (q->rate_flags & CAKE_FLAG_OVERHEAD)
1277 len -= off;
1278
1279 if (q->max_netlen < len)
1280 q->max_netlen = len;
1281 if (q->min_netlen > len)
1282 q->min_netlen = len;
1283
1284 len += q->rate_overhead;
1285
1286 if (len < q->rate_mpu)
1287 len = q->rate_mpu;
1288
1289 if (q->atm_mode == CAKE_ATM_ATM) {
1290 len += 47;
1291 len /= 48;
1292 len *= 53;
1293 } else if (q->atm_mode == CAKE_ATM_PTM) {
1294 /* Add one byte per 64 bytes or part thereof.
1295 * This is conservative and easier to calculate than the
1296 * precise value.
1297 */
1298 len += (len + 63) / 64;
1299 }
1300
1301 if (q->max_adjlen < len)
1302 q->max_adjlen = len;
1303 if (q->min_adjlen > len)
1304 q->min_adjlen = len;
1305
1306 return len;
1307}
1308
1309static u32 cake_overhead(struct cake_sched_data *q, const struct sk_buff *skb)
1310{
1311 const struct skb_shared_info *shinfo = skb_shinfo(skb);
1312 unsigned int hdr_len, last_len = 0;
1313 u32 off = skb_network_offset(skb);
1314 u32 len = qdisc_pkt_len(skb);
1315 u16 segs = 1;
1316
1317 q->avg_netoff = cake_ewma(q->avg_netoff, off << 16, 8);
1318
1319 if (!shinfo->gso_size)
1320 return cake_calc_overhead(q, len, off);
1321
1322 /* borrowed from qdisc_pkt_len_init() */
1323 hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
1324
1325 /* + transport layer */
1326 if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 |
1327 SKB_GSO_TCPV6))) {
1328 const struct tcphdr *th;
1329 struct tcphdr _tcphdr;
1330
1331 th = skb_header_pointer(skb, skb_transport_offset(skb),
1332 sizeof(_tcphdr), &_tcphdr);
1333 if (likely(th))
1334 hdr_len += __tcp_hdrlen(th);
1335 } else {
1336 struct udphdr _udphdr;
1337
1338 if (skb_header_pointer(skb, skb_transport_offset(skb),
1339 sizeof(_udphdr), &_udphdr))
1340 hdr_len += sizeof(struct udphdr);
1341 }
1342
1343 if (unlikely(shinfo->gso_type & SKB_GSO_DODGY))
1344 segs = DIV_ROUND_UP(skb->len - hdr_len,
1345 shinfo->gso_size);
1346 else
1347 segs = shinfo->gso_segs;
1348
1349 len = shinfo->gso_size + hdr_len;
1350 last_len = skb->len - shinfo->gso_size * (segs - 1);
1351
1352 return (cake_calc_overhead(q, len, off) * (segs - 1) +
1353 cake_calc_overhead(q, last_len, off));
1354}
1355
1356static void cake_heap_swap(struct cake_sched_data *q, u16 i, u16 j)
1357{
1358 struct cake_heap_entry ii = q->overflow_heap[i];
1359 struct cake_heap_entry jj = q->overflow_heap[j];
1360
1361 q->overflow_heap[i] = jj;
1362 q->overflow_heap[j] = ii;
1363
1364 q->tins[ii.t].overflow_idx[ii.b] = j;
1365 q->tins[jj.t].overflow_idx[jj.b] = i;
1366}
1367
1368static u32 cake_heap_get_backlog(const struct cake_sched_data *q, u16 i)
1369{
1370 struct cake_heap_entry ii = q->overflow_heap[i];
1371
1372 return q->tins[ii.t].backlogs[ii.b];
1373}
1374
1375static void cake_heapify(struct cake_sched_data *q, u16 i)
1376{
1377 static const u32 a = CAKE_MAX_TINS * CAKE_QUEUES;
1378 u32 mb = cake_heap_get_backlog(q, i);
1379 u32 m = i;
1380
1381 while (m < a) {
1382 u32 l = m + m + 1;
1383 u32 r = l + 1;
1384
1385 if (l < a) {
1386 u32 lb = cake_heap_get_backlog(q, l);
1387
1388 if (lb > mb) {
1389 m = l;
1390 mb = lb;
1391 }
1392 }
1393
1394 if (r < a) {
1395 u32 rb = cake_heap_get_backlog(q, r);
1396
1397 if (rb > mb) {
1398 m = r;
1399 mb = rb;
1400 }
1401 }
1402
1403 if (m != i) {
1404 cake_heap_swap(q, i, m);
1405 i = m;
1406 } else {
1407 break;
1408 }
1409 }
1410}
1411
1412static void cake_heapify_up(struct cake_sched_data *q, u16 i)
1413{
1414 while (i > 0 && i < CAKE_MAX_TINS * CAKE_QUEUES) {
1415 u16 p = (i - 1) >> 1;
1416 u32 ib = cake_heap_get_backlog(q, i);
1417 u32 pb = cake_heap_get_backlog(q, p);
1418
1419 if (ib > pb) {
1420 cake_heap_swap(q, i, p);
1421 i = p;
1422 } else {
1423 break;
1424 }
1425 }
1426}
1427
1428static int cake_advance_shaper(struct cake_sched_data *q,
1429 struct cake_tin_data *b,
1430 struct sk_buff *skb,
1431 ktime_t now, bool drop)
1432{
1433 u32 len = get_cobalt_cb(skb)->adjusted_len;
1434
1435 /* charge packet bandwidth to this tin
1436 * and to the global shaper.
1437 */
1438 if (q->rate_ns) {
1439 u64 tin_dur = (len * b->tin_rate_ns) >> b->tin_rate_shft;
1440 u64 global_dur = (len * q->rate_ns) >> q->rate_shft;
1441 u64 failsafe_dur = global_dur + (global_dur >> 1);
1442
1443 if (ktime_before(b->time_next_packet, now))
1444 b->time_next_packet = ktime_add_ns(b->time_next_packet,
1445 tin_dur);
1446
1447 else if (ktime_before(b->time_next_packet,
1448 ktime_add_ns(now, tin_dur)))
1449 b->time_next_packet = ktime_add_ns(now, tin_dur);
1450
1451 q->time_next_packet = ktime_add_ns(q->time_next_packet,
1452 global_dur);
1453 if (!drop)
1454 q->failsafe_next_packet = \
1455 ktime_add_ns(q->failsafe_next_packet,
1456 failsafe_dur);
1457 }
1458 return len;
1459}
1460
1461static unsigned int cake_drop(struct Qdisc *sch, struct sk_buff **to_free)
1462{
1463 struct cake_sched_data *q = qdisc_priv(sch);
1464 ktime_t now = ktime_get();
1465 u32 idx = 0, tin = 0, len;
1466 struct cake_heap_entry qq;
1467 struct cake_tin_data *b;
1468 struct cake_flow *flow;
1469 struct sk_buff *skb;
1470
1471 if (!q->overflow_timeout) {
1472 int i;
1473 /* Build fresh max-heap */
1474 for (i = CAKE_MAX_TINS * CAKE_QUEUES / 2; i >= 0; i--)
1475 cake_heapify(q, i);
1476 }
1477 q->overflow_timeout = 65535;
1478
1479 /* select longest queue for pruning */
1480 qq = q->overflow_heap[0];
1481 tin = qq.t;
1482 idx = qq.b;
1483
1484 b = &q->tins[tin];
1485 flow = &b->flows[idx];
1486 skb = dequeue_head(flow);
1487 if (unlikely(!skb)) {
1488 /* heap has gone wrong, rebuild it next time */
1489 q->overflow_timeout = 0;
1490 return idx + (tin << 16);
1491 }
1492
1493 if (cobalt_queue_full(&flow->cvars, &b->cparams, now))
1494 b->unresponsive_flow_count++;
1495
1496 len = qdisc_pkt_len(skb);
1497 q->buffer_used -= skb->truesize;
1498 b->backlogs[idx] -= len;
1499 b->tin_backlog -= len;
1500 sch->qstats.backlog -= len;
1501 qdisc_tree_reduce_backlog(sch, 1, len);
1502
1503 flow->dropped++;
1504 b->tin_dropped++;
1505 sch->qstats.drops++;
1506
1507 if (q->rate_flags & CAKE_FLAG_INGRESS)
1508 cake_advance_shaper(q, b, skb, now, true);
1509
1510 __qdisc_drop(skb, to_free);
1511 sch->q.qlen--;
1512
1513 cake_heapify(q, 0);
1514
1515 return idx + (tin << 16);
1516}
1517
1518static u8 cake_handle_diffserv(struct sk_buff *skb, u16 wash)
1519{
1520 int wlen = skb_network_offset(skb);
1521 u8 dscp;
1522
1523 switch (tc_skb_protocol(skb)) {
1524 case htons(ETH_P_IP):
1525 wlen += sizeof(struct iphdr);
1526 if (!pskb_may_pull(skb, wlen) ||
1527 skb_try_make_writable(skb, wlen))
1528 return 0;
1529
1530 dscp = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
1531 if (wash && dscp)
1532 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, 0);
1533 return dscp;
1534
1535 case htons(ETH_P_IPV6):
1536 wlen += sizeof(struct ipv6hdr);
1537 if (!pskb_may_pull(skb, wlen) ||
1538 skb_try_make_writable(skb, wlen))
1539 return 0;
1540
1541 dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2;
1542 if (wash && dscp)
1543 ipv6_change_dsfield(ipv6_hdr(skb), INET_ECN_MASK, 0);
1544 return dscp;
1545
1546 case htons(ETH_P_ARP):
1547 return 0x38; /* CS7 - Net Control */
1548
1549 default:
1550 /* If there is no Diffserv field, treat as best-effort */
1551 return 0;
1552 }
1553}
1554
1555static struct cake_tin_data *cake_select_tin(struct Qdisc *sch,
1556 struct sk_buff *skb)
1557{
1558 struct cake_sched_data *q = qdisc_priv(sch);
1559 u32 tin, mark;
1560 u8 dscp;
1561
1562 /* Tin selection: Default to diffserv-based selection, allow overriding
1563 * using firewall marks or skb->priority.
1564 */
1565 dscp = cake_handle_diffserv(skb,
1566 q->rate_flags & CAKE_FLAG_WASH);
1567 mark = (skb->mark & q->fwmark_mask) >> q->fwmark_shft;
1568
1569 if (q->tin_mode == CAKE_DIFFSERV_BESTEFFORT)
1570 tin = 0;
1571
1572 else if (mark && mark <= q->tin_cnt)
1573 tin = q->tin_order[mark - 1];
1574
1575 else if (TC_H_MAJ(skb->priority) == sch->handle &&
1576 TC_H_MIN(skb->priority) > 0 &&
1577 TC_H_MIN(skb->priority) <= q->tin_cnt)
1578 tin = q->tin_order[TC_H_MIN(skb->priority) - 1];
1579
1580 else {
1581 tin = q->tin_index[dscp];
1582
1583 if (unlikely(tin >= q->tin_cnt))
1584 tin = 0;
1585 }
1586
1587 return &q->tins[tin];
1588}
1589
1590static u32 cake_classify(struct Qdisc *sch, struct cake_tin_data **t,
1591 struct sk_buff *skb, int flow_mode, int *qerr)
1592{
1593 struct cake_sched_data *q = qdisc_priv(sch);
1594 struct tcf_proto *filter;
1595 struct tcf_result res;
1596 u16 flow = 0, host = 0;
1597 int result;
1598
1599 filter = rcu_dereference_bh(q->filter_list);
1600 if (!filter)
1601 goto hash;
1602
1603 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
1604 result = tcf_classify(skb, filter, &res, false);
1605
1606 if (result >= 0) {
1607#ifdef CONFIG_NET_CLS_ACT
1608 switch (result) {
1609 case TC_ACT_STOLEN:
1610 case TC_ACT_QUEUED:
1611 case TC_ACT_TRAP:
1612 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
1613 /* fall through */
1614 case TC_ACT_SHOT:
1615 return 0;
1616 }
1617#endif
1618 if (TC_H_MIN(res.classid) <= CAKE_QUEUES)
1619 flow = TC_H_MIN(res.classid);
1620 if (TC_H_MAJ(res.classid) <= (CAKE_QUEUES << 16))
1621 host = TC_H_MAJ(res.classid) >> 16;
1622 }
1623hash:
1624 *t = cake_select_tin(sch, skb);
1625 return cake_hash(*t, skb, flow_mode, flow, host) + 1;
1626}
1627
1628static void cake_reconfigure(struct Qdisc *sch);
1629
1630static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
1631 struct sk_buff **to_free)
1632{
1633 struct cake_sched_data *q = qdisc_priv(sch);
1634 int len = qdisc_pkt_len(skb);
1635 int uninitialized_var(ret);
1636 struct sk_buff *ack = NULL;
1637 ktime_t now = ktime_get();
1638 struct cake_tin_data *b;
1639 struct cake_flow *flow;
1640 u32 idx;
1641
1642 /* choose flow to insert into */
1643 idx = cake_classify(sch, &b, skb, q->flow_mode, &ret);
1644 if (idx == 0) {
1645 if (ret & __NET_XMIT_BYPASS)
1646 qdisc_qstats_drop(sch);
1647 __qdisc_drop(skb, to_free);
1648 return ret;
1649 }
1650 idx--;
1651 flow = &b->flows[idx];
1652
1653 /* ensure shaper state isn't stale */
1654 if (!b->tin_backlog) {
1655 if (ktime_before(b->time_next_packet, now))
1656 b->time_next_packet = now;
1657
1658 if (!sch->q.qlen) {
1659 if (ktime_before(q->time_next_packet, now)) {
1660 q->failsafe_next_packet = now;
1661 q->time_next_packet = now;
1662 } else if (ktime_after(q->time_next_packet, now) &&
1663 ktime_after(q->failsafe_next_packet, now)) {
1664 u64 next = \
1665 min(ktime_to_ns(q->time_next_packet),
1666 ktime_to_ns(
1667 q->failsafe_next_packet));
1668 sch->qstats.overlimits++;
1669 qdisc_watchdog_schedule_ns(&q->watchdog, next);
1670 }
1671 }
1672 }
1673
1674 if (unlikely(len > b->max_skblen))
1675 b->max_skblen = len;
1676
1677 if (skb_is_gso(skb) && q->rate_flags & CAKE_FLAG_SPLIT_GSO) {
1678 struct sk_buff *segs, *nskb;
1679 netdev_features_t features = netif_skb_features(skb);
1680 unsigned int slen = 0, numsegs = 0;
1681
1682 segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
1683 if (IS_ERR_OR_NULL(segs))
1684 return qdisc_drop(skb, sch, to_free);
1685
1686 while (segs) {
1687 nskb = segs->next;
1688 skb_mark_not_on_list(segs);
1689 qdisc_skb_cb(segs)->pkt_len = segs->len;
1690 cobalt_set_enqueue_time(segs, now);
1691 get_cobalt_cb(segs)->adjusted_len = cake_overhead(q,
1692 segs);
1693 flow_queue_add(flow, segs);
1694
1695 sch->q.qlen++;
1696 numsegs++;
1697 slen += segs->len;
1698 q->buffer_used += segs->truesize;
1699 b->packets++;
1700 segs = nskb;
1701 }
1702
1703 /* stats */
1704 b->bytes += slen;
1705 b->backlogs[idx] += slen;
1706 b->tin_backlog += slen;
1707 sch->qstats.backlog += slen;
1708 q->avg_window_bytes += slen;
1709
1710 qdisc_tree_reduce_backlog(sch, 1-numsegs, len-slen);
1711 consume_skb(skb);
1712 } else {
1713 /* not splitting */
1714 cobalt_set_enqueue_time(skb, now);
1715 get_cobalt_cb(skb)->adjusted_len = cake_overhead(q, skb);
1716 flow_queue_add(flow, skb);
1717
1718 if (q->ack_filter)
1719 ack = cake_ack_filter(q, flow);
1720
1721 if (ack) {
1722 b->ack_drops++;
1723 sch->qstats.drops++;
1724 b->bytes += qdisc_pkt_len(ack);
1725 len -= qdisc_pkt_len(ack);
1726 q->buffer_used += skb->truesize - ack->truesize;
1727 if (q->rate_flags & CAKE_FLAG_INGRESS)
1728 cake_advance_shaper(q, b, ack, now, true);
1729
1730 qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(ack));
1731 consume_skb(ack);
1732 } else {
1733 sch->q.qlen++;
1734 q->buffer_used += skb->truesize;
1735 }
1736
1737 /* stats */
1738 b->packets++;
1739 b->bytes += len;
1740 b->backlogs[idx] += len;
1741 b->tin_backlog += len;
1742 sch->qstats.backlog += len;
1743 q->avg_window_bytes += len;
1744 }
1745
1746 if (q->overflow_timeout)
1747 cake_heapify_up(q, b->overflow_idx[idx]);
1748
1749 /* incoming bandwidth capacity estimate */
1750 if (q->rate_flags & CAKE_FLAG_AUTORATE_INGRESS) {
1751 u64 packet_interval = \
1752 ktime_to_ns(ktime_sub(now, q->last_packet_time));
1753
1754 if (packet_interval > NSEC_PER_SEC)
1755 packet_interval = NSEC_PER_SEC;
1756
1757 /* filter out short-term bursts, eg. wifi aggregation */
1758 q->avg_packet_interval = \
1759 cake_ewma(q->avg_packet_interval,
1760 packet_interval,
1761 (packet_interval > q->avg_packet_interval ?
1762 2 : 8));
1763
1764 q->last_packet_time = now;
1765
1766 if (packet_interval > q->avg_packet_interval) {
1767 u64 window_interval = \
1768 ktime_to_ns(ktime_sub(now,
1769 q->avg_window_begin));
1770 u64 b = q->avg_window_bytes * (u64)NSEC_PER_SEC;
1771
1772 do_div(b, window_interval);
1773 q->avg_peak_bandwidth =
1774 cake_ewma(q->avg_peak_bandwidth, b,
1775 b > q->avg_peak_bandwidth ? 2 : 8);
1776 q->avg_window_bytes = 0;
1777 q->avg_window_begin = now;
1778
1779 if (ktime_after(now,
1780 ktime_add_ms(q->last_reconfig_time,
1781 250))) {
1782 q->rate_bps = (q->avg_peak_bandwidth * 15) >> 4;
1783 cake_reconfigure(sch);
1784 }
1785 }
1786 } else {
1787 q->avg_window_bytes = 0;
1788 q->last_packet_time = now;
1789 }
1790
1791 /* flowchain */
1792 if (!flow->set || flow->set == CAKE_SET_DECAYING) {
1793 struct cake_host *srchost = &b->hosts[flow->srchost];
1794 struct cake_host *dsthost = &b->hosts[flow->dsthost];
1795 u16 host_load = 1;
1796
1797 if (!flow->set) {
1798 list_add_tail(&flow->flowchain, &b->new_flows);
1799 } else {
1800 b->decaying_flow_count--;
1801 list_move_tail(&flow->flowchain, &b->new_flows);
1802 }
1803 flow->set = CAKE_SET_SPARSE;
1804 b->sparse_flow_count++;
1805
1806 if (cake_dsrc(q->flow_mode))
1807 host_load = max(host_load, srchost->srchost_bulk_flow_count);
1808
1809 if (cake_ddst(q->flow_mode))
1810 host_load = max(host_load, dsthost->dsthost_bulk_flow_count);
1811
1812 flow->deficit = (b->flow_quantum *
1813 quantum_div[host_load]) >> 16;
1814 } else if (flow->set == CAKE_SET_SPARSE_WAIT) {
1815 struct cake_host *srchost = &b->hosts[flow->srchost];
1816 struct cake_host *dsthost = &b->hosts[flow->dsthost];
1817
1818 /* this flow was empty, accounted as a sparse flow, but actually
1819 * in the bulk rotation.
1820 */
1821 flow->set = CAKE_SET_BULK;
1822 b->sparse_flow_count--;
1823 b->bulk_flow_count++;
1824
1825 if (cake_dsrc(q->flow_mode))
1826 srchost->srchost_bulk_flow_count++;
1827
1828 if (cake_ddst(q->flow_mode))
1829 dsthost->dsthost_bulk_flow_count++;
1830
1831 }
1832
1833 if (q->buffer_used > q->buffer_max_used)
1834 q->buffer_max_used = q->buffer_used;
1835
1836 if (q->buffer_used > q->buffer_limit) {
1837 u32 dropped = 0;
1838
1839 while (q->buffer_used > q->buffer_limit) {
1840 dropped++;
1841 cake_drop(sch, to_free);
1842 }
1843 b->drop_overlimit += dropped;
1844 }
1845 return NET_XMIT_SUCCESS;
1846}
1847
1848static struct sk_buff *cake_dequeue_one(struct Qdisc *sch)
1849{
1850 struct cake_sched_data *q = qdisc_priv(sch);
1851 struct cake_tin_data *b = &q->tins[q->cur_tin];
1852 struct cake_flow *flow = &b->flows[q->cur_flow];
1853 struct sk_buff *skb = NULL;
1854 u32 len;
1855
1856 if (flow->head) {
1857 skb = dequeue_head(flow);
1858 len = qdisc_pkt_len(skb);
1859 b->backlogs[q->cur_flow] -= len;
1860 b->tin_backlog -= len;
1861 sch->qstats.backlog -= len;
1862 q->buffer_used -= skb->truesize;
1863 sch->q.qlen--;
1864
1865 if (q->overflow_timeout)
1866 cake_heapify(q, b->overflow_idx[q->cur_flow]);
1867 }
1868 return skb;
1869}
1870
1871/* Discard leftover packets from a tin no longer in use. */
1872static void cake_clear_tin(struct Qdisc *sch, u16 tin)
1873{
1874 struct cake_sched_data *q = qdisc_priv(sch);
1875 struct sk_buff *skb;
1876
1877 q->cur_tin = tin;
1878 for (q->cur_flow = 0; q->cur_flow < CAKE_QUEUES; q->cur_flow++)
1879 while (!!(skb = cake_dequeue_one(sch)))
1880 kfree_skb(skb);
1881}
1882
1883static struct sk_buff *cake_dequeue(struct Qdisc *sch)
1884{
1885 struct cake_sched_data *q = qdisc_priv(sch);
1886 struct cake_tin_data *b = &q->tins[q->cur_tin];
1887 struct cake_host *srchost, *dsthost;
1888 ktime_t now = ktime_get();
1889 struct cake_flow *flow;
1890 struct list_head *head;
1891 bool first_flow = true;
1892 struct sk_buff *skb;
1893 u16 host_load;
1894 u64 delay;
1895 u32 len;
1896
1897begin:
1898 if (!sch->q.qlen)
1899 return NULL;
1900
1901 /* global hard shaper */
1902 if (ktime_after(q->time_next_packet, now) &&
1903 ktime_after(q->failsafe_next_packet, now)) {
1904 u64 next = min(ktime_to_ns(q->time_next_packet),
1905 ktime_to_ns(q->failsafe_next_packet));
1906
1907 sch->qstats.overlimits++;
1908 qdisc_watchdog_schedule_ns(&q->watchdog, next);
1909 return NULL;
1910 }
1911
1912 /* Choose a class to work on. */
1913 if (!q->rate_ns) {
1914 /* In unlimited mode, can't rely on shaper timings, just balance
1915 * with DRR
1916 */
1917 bool wrapped = false, empty = true;
1918
1919 while (b->tin_deficit < 0 ||
1920 !(b->sparse_flow_count + b->bulk_flow_count)) {
1921 if (b->tin_deficit <= 0)
1922 b->tin_deficit += b->tin_quantum_band;
1923 if (b->sparse_flow_count + b->bulk_flow_count)
1924 empty = false;
1925
1926 q->cur_tin++;
1927 b++;
1928 if (q->cur_tin >= q->tin_cnt) {
1929 q->cur_tin = 0;
1930 b = q->tins;
1931
1932 if (wrapped) {
1933 /* It's possible for q->qlen to be
1934 * nonzero when we actually have no
1935 * packets anywhere.
1936 */
1937 if (empty)
1938 return NULL;
1939 } else {
1940 wrapped = true;
1941 }
1942 }
1943 }
1944 } else {
1945 /* In shaped mode, choose:
1946 * - Highest-priority tin with queue and meeting schedule, or
1947 * - The earliest-scheduled tin with queue.
1948 */
1949 ktime_t best_time = KTIME_MAX;
1950 int tin, best_tin = 0;
1951
1952 for (tin = 0; tin < q->tin_cnt; tin++) {
1953 b = q->tins + tin;
1954 if ((b->sparse_flow_count + b->bulk_flow_count) > 0) {
1955 ktime_t time_to_pkt = \
1956 ktime_sub(b->time_next_packet, now);
1957
1958 if (ktime_to_ns(time_to_pkt) <= 0 ||
1959 ktime_compare(time_to_pkt,
1960 best_time) <= 0) {
1961 best_time = time_to_pkt;
1962 best_tin = tin;
1963 }
1964 }
1965 }
1966
1967 q->cur_tin = best_tin;
1968 b = q->tins + best_tin;
1969
1970 /* No point in going further if no packets to deliver. */
1971 if (unlikely(!(b->sparse_flow_count + b->bulk_flow_count)))
1972 return NULL;
1973 }
1974
1975retry:
1976 /* service this class */
1977 head = &b->decaying_flows;
1978 if (!first_flow || list_empty(head)) {
1979 head = &b->new_flows;
1980 if (list_empty(head)) {
1981 head = &b->old_flows;
1982 if (unlikely(list_empty(head))) {
1983 head = &b->decaying_flows;
1984 if (unlikely(list_empty(head)))
1985 goto begin;
1986 }
1987 }
1988 }
1989 flow = list_first_entry(head, struct cake_flow, flowchain);
1990 q->cur_flow = flow - b->flows;
1991 first_flow = false;
1992
1993 /* triple isolation (modified DRR++) */
1994 srchost = &b->hosts[flow->srchost];
1995 dsthost = &b->hosts[flow->dsthost];
1996 host_load = 1;
1997
1998 /* flow isolation (DRR++) */
1999 if (flow->deficit <= 0) {
2000 /* Keep all flows with deficits out of the sparse and decaying
2001 * rotations. No non-empty flow can go into the decaying
2002 * rotation, so they can't get deficits
2003 */
2004 if (flow->set == CAKE_SET_SPARSE) {
2005 if (flow->head) {
2006 b->sparse_flow_count--;
2007 b->bulk_flow_count++;
2008
2009 if (cake_dsrc(q->flow_mode))
2010 srchost->srchost_bulk_flow_count++;
2011
2012 if (cake_ddst(q->flow_mode))
2013 dsthost->dsthost_bulk_flow_count++;
2014
2015 flow->set = CAKE_SET_BULK;
2016 } else {
2017 /* we've moved it to the bulk rotation for
2018 * correct deficit accounting but we still want
2019 * to count it as a sparse flow, not a bulk one.
2020 */
2021 flow->set = CAKE_SET_SPARSE_WAIT;
2022 }
2023 }
2024
2025 if (cake_dsrc(q->flow_mode))
2026 host_load = max(host_load, srchost->srchost_bulk_flow_count);
2027
2028 if (cake_ddst(q->flow_mode))
2029 host_load = max(host_load, dsthost->dsthost_bulk_flow_count);
2030
2031 WARN_ON(host_load > CAKE_QUEUES);
2032
2033 /* The shifted prandom_u32() is a way to apply dithering to
2034 * avoid accumulating roundoff errors
2035 */
2036 flow->deficit += (b->flow_quantum * quantum_div[host_load] +
2037 (prandom_u32() >> 16)) >> 16;
2038 list_move_tail(&flow->flowchain, &b->old_flows);
2039
2040 goto retry;
2041 }
2042
2043 /* Retrieve a packet via the AQM */
2044 while (1) {
2045 skb = cake_dequeue_one(sch);
2046 if (!skb) {
2047 /* this queue was actually empty */
2048 if (cobalt_queue_empty(&flow->cvars, &b->cparams, now))
2049 b->unresponsive_flow_count--;
2050
2051 if (flow->cvars.p_drop || flow->cvars.count ||
2052 ktime_before(now, flow->cvars.drop_next)) {
2053 /* keep in the flowchain until the state has
2054 * decayed to rest
2055 */
2056 list_move_tail(&flow->flowchain,
2057 &b->decaying_flows);
2058 if (flow->set == CAKE_SET_BULK) {
2059 b->bulk_flow_count--;
2060
2061 if (cake_dsrc(q->flow_mode))
2062 srchost->srchost_bulk_flow_count--;
2063
2064 if (cake_ddst(q->flow_mode))
2065 dsthost->dsthost_bulk_flow_count--;
2066
2067 b->decaying_flow_count++;
2068 } else if (flow->set == CAKE_SET_SPARSE ||
2069 flow->set == CAKE_SET_SPARSE_WAIT) {
2070 b->sparse_flow_count--;
2071 b->decaying_flow_count++;
2072 }
2073 flow->set = CAKE_SET_DECAYING;
2074 } else {
2075 /* remove empty queue from the flowchain */
2076 list_del_init(&flow->flowchain);
2077 if (flow->set == CAKE_SET_SPARSE ||
2078 flow->set == CAKE_SET_SPARSE_WAIT)
2079 b->sparse_flow_count--;
2080 else if (flow->set == CAKE_SET_BULK) {
2081 b->bulk_flow_count--;
2082
2083 if (cake_dsrc(q->flow_mode))
2084 srchost->srchost_bulk_flow_count--;
2085
2086 if (cake_ddst(q->flow_mode))
2087 dsthost->dsthost_bulk_flow_count--;
2088
2089 } else
2090 b->decaying_flow_count--;
2091
2092 flow->set = CAKE_SET_NONE;
2093 }
2094 goto begin;
2095 }
2096
2097 /* Last packet in queue may be marked, shouldn't be dropped */
2098 if (!cobalt_should_drop(&flow->cvars, &b->cparams, now, skb,
2099 (b->bulk_flow_count *
2100 !!(q->rate_flags &
2101 CAKE_FLAG_INGRESS))) ||
2102 !flow->head)
2103 break;
2104
2105 /* drop this packet, get another one */
2106 if (q->rate_flags & CAKE_FLAG_INGRESS) {
2107 len = cake_advance_shaper(q, b, skb,
2108 now, true);
2109 flow->deficit -= len;
2110 b->tin_deficit -= len;
2111 }
2112 flow->dropped++;
2113 b->tin_dropped++;
2114 qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(skb));
2115 qdisc_qstats_drop(sch);
2116 kfree_skb(skb);
2117 if (q->rate_flags & CAKE_FLAG_INGRESS)
2118 goto retry;
2119 }
2120
2121 b->tin_ecn_mark += !!flow->cvars.ecn_marked;
2122 qdisc_bstats_update(sch, skb);
2123
2124 /* collect delay stats */
2125 delay = ktime_to_ns(ktime_sub(now, cobalt_get_enqueue_time(skb)));
2126 b->avge_delay = cake_ewma(b->avge_delay, delay, 8);
2127 b->peak_delay = cake_ewma(b->peak_delay, delay,
2128 delay > b->peak_delay ? 2 : 8);
2129 b->base_delay = cake_ewma(b->base_delay, delay,
2130 delay < b->base_delay ? 2 : 8);
2131
2132 len = cake_advance_shaper(q, b, skb, now, false);
2133 flow->deficit -= len;
2134 b->tin_deficit -= len;
2135
2136 if (ktime_after(q->time_next_packet, now) && sch->q.qlen) {
2137 u64 next = min(ktime_to_ns(q->time_next_packet),
2138 ktime_to_ns(q->failsafe_next_packet));
2139
2140 qdisc_watchdog_schedule_ns(&q->watchdog, next);
2141 } else if (!sch->q.qlen) {
2142 int i;
2143
2144 for (i = 0; i < q->tin_cnt; i++) {
2145 if (q->tins[i].decaying_flow_count) {
2146 ktime_t next = \
2147 ktime_add_ns(now,
2148 q->tins[i].cparams.target);
2149
2150 qdisc_watchdog_schedule_ns(&q->watchdog,
2151 ktime_to_ns(next));
2152 break;
2153 }
2154 }
2155 }
2156
2157 if (q->overflow_timeout)
2158 q->overflow_timeout--;
2159
2160 return skb;
2161}
2162
2163static void cake_reset(struct Qdisc *sch)
2164{
2165 u32 c;
2166
2167 for (c = 0; c < CAKE_MAX_TINS; c++)
2168 cake_clear_tin(sch, c);
2169}
2170
2171static const struct nla_policy cake_policy[TCA_CAKE_MAX + 1] = {
2172 [TCA_CAKE_BASE_RATE64] = { .type = NLA_U64 },
2173 [TCA_CAKE_DIFFSERV_MODE] = { .type = NLA_U32 },
2174 [TCA_CAKE_ATM] = { .type = NLA_U32 },
2175 [TCA_CAKE_FLOW_MODE] = { .type = NLA_U32 },
2176 [TCA_CAKE_OVERHEAD] = { .type = NLA_S32 },
2177 [TCA_CAKE_RTT] = { .type = NLA_U32 },
2178 [TCA_CAKE_TARGET] = { .type = NLA_U32 },
2179 [TCA_CAKE_AUTORATE] = { .type = NLA_U32 },
2180 [TCA_CAKE_MEMORY] = { .type = NLA_U32 },
2181 [TCA_CAKE_NAT] = { .type = NLA_U32 },
2182 [TCA_CAKE_RAW] = { .type = NLA_U32 },
2183 [TCA_CAKE_WASH] = { .type = NLA_U32 },
2184 [TCA_CAKE_MPU] = { .type = NLA_U32 },
2185 [TCA_CAKE_INGRESS] = { .type = NLA_U32 },
2186 [TCA_CAKE_ACK_FILTER] = { .type = NLA_U32 },
2187 [TCA_CAKE_FWMARK] = { .type = NLA_U32 },
2188};
2189
2190static void cake_set_rate(struct cake_tin_data *b, u64 rate, u32 mtu,
2191 u64 target_ns, u64 rtt_est_ns)
2192{
2193 /* convert byte-rate into time-per-byte
2194 * so it will always unwedge in reasonable time.
2195 */
2196 static const u64 MIN_RATE = 64;
2197 u32 byte_target = mtu;
2198 u64 byte_target_ns;
2199 u8 rate_shft = 0;
2200 u64 rate_ns = 0;
2201
2202 b->flow_quantum = 1514;
2203 if (rate) {
2204 b->flow_quantum = max(min(rate >> 12, 1514ULL), 300ULL);
2205 rate_shft = 34;
2206 rate_ns = ((u64)NSEC_PER_SEC) << rate_shft;
2207 rate_ns = div64_u64(rate_ns, max(MIN_RATE, rate));
2208 while (!!(rate_ns >> 34)) {
2209 rate_ns >>= 1;
2210 rate_shft--;
2211 }
2212 } /* else unlimited, ie. zero delay */
2213
2214 b->tin_rate_bps = rate;
2215 b->tin_rate_ns = rate_ns;
2216 b->tin_rate_shft = rate_shft;
2217
2218 byte_target_ns = (byte_target * rate_ns) >> rate_shft;
2219
2220 b->cparams.target = max((byte_target_ns * 3) / 2, target_ns);
2221 b->cparams.interval = max(rtt_est_ns +
2222 b->cparams.target - target_ns,
2223 b->cparams.target * 2);
2224 b->cparams.mtu_time = byte_target_ns;
2225 b->cparams.p_inc = 1 << 24; /* 1/256 */
2226 b->cparams.p_dec = 1 << 20; /* 1/4096 */
2227}
2228
2229static int cake_config_besteffort(struct Qdisc *sch)
2230{
2231 struct cake_sched_data *q = qdisc_priv(sch);
2232 struct cake_tin_data *b = &q->tins[0];
2233 u32 mtu = psched_mtu(qdisc_dev(sch));
2234 u64 rate = q->rate_bps;
2235
2236 q->tin_cnt = 1;
2237
2238 q->tin_index = besteffort;
2239 q->tin_order = normal_order;
2240
2241 cake_set_rate(b, rate, mtu,
2242 us_to_ns(q->target), us_to_ns(q->interval));
2243 b->tin_quantum_band = 65535;
2244 b->tin_quantum_prio = 65535;
2245
2246 return 0;
2247}
2248
2249static int cake_config_precedence(struct Qdisc *sch)
2250{
2251 /* convert high-level (user visible) parameters into internal format */
2252 struct cake_sched_data *q = qdisc_priv(sch);
2253 u32 mtu = psched_mtu(qdisc_dev(sch));
2254 u64 rate = q->rate_bps;
2255 u32 quantum1 = 256;
2256 u32 quantum2 = 256;
2257 u32 i;
2258
2259 q->tin_cnt = 8;
2260 q->tin_index = precedence;
2261 q->tin_order = normal_order;
2262
2263 for (i = 0; i < q->tin_cnt; i++) {
2264 struct cake_tin_data *b = &q->tins[i];
2265
2266 cake_set_rate(b, rate, mtu, us_to_ns(q->target),
2267 us_to_ns(q->interval));
2268
2269 b->tin_quantum_prio = max_t(u16, 1U, quantum1);
2270 b->tin_quantum_band = max_t(u16, 1U, quantum2);
2271
2272 /* calculate next class's parameters */
2273 rate *= 7;
2274 rate >>= 3;
2275
2276 quantum1 *= 3;
2277 quantum1 >>= 1;
2278
2279 quantum2 *= 7;
2280 quantum2 >>= 3;
2281 }
2282
2283 return 0;
2284}
2285
2286/* List of known Diffserv codepoints:
2287 *
2288 * Least Effort (CS1)
2289 * Best Effort (CS0)
2290 * Max Reliability & LLT "Lo" (TOS1)
2291 * Max Throughput (TOS2)
2292 * Min Delay (TOS4)
2293 * LLT "La" (TOS5)
2294 * Assured Forwarding 1 (AF1x) - x3
2295 * Assured Forwarding 2 (AF2x) - x3
2296 * Assured Forwarding 3 (AF3x) - x3
2297 * Assured Forwarding 4 (AF4x) - x3
2298 * Precedence Class 2 (CS2)
2299 * Precedence Class 3 (CS3)
2300 * Precedence Class 4 (CS4)
2301 * Precedence Class 5 (CS5)
2302 * Precedence Class 6 (CS6)
2303 * Precedence Class 7 (CS7)
2304 * Voice Admit (VA)
2305 * Expedited Forwarding (EF)
2306
2307 * Total 25 codepoints.
2308 */
2309
2310/* List of traffic classes in RFC 4594:
2311 * (roughly descending order of contended priority)
2312 * (roughly ascending order of uncontended throughput)
2313 *
2314 * Network Control (CS6,CS7) - routing traffic
2315 * Telephony (EF,VA) - aka. VoIP streams
2316 * Signalling (CS5) - VoIP setup
2317 * Multimedia Conferencing (AF4x) - aka. video calls
2318 * Realtime Interactive (CS4) - eg. games
2319 * Multimedia Streaming (AF3x) - eg. YouTube, NetFlix, Twitch
2320 * Broadcast Video (CS3)
2321 * Low Latency Data (AF2x,TOS4) - eg. database
2322 * Ops, Admin, Management (CS2,TOS1) - eg. ssh
2323 * Standard Service (CS0 & unrecognised codepoints)
2324 * High Throughput Data (AF1x,TOS2) - eg. web traffic
2325 * Low Priority Data (CS1) - eg. BitTorrent
2326
2327 * Total 12 traffic classes.
2328 */
2329
2330static int cake_config_diffserv8(struct Qdisc *sch)
2331{
2332/* Pruned list of traffic classes for typical applications:
2333 *
2334 * Network Control (CS6, CS7)
2335 * Minimum Latency (EF, VA, CS5, CS4)
2336 * Interactive Shell (CS2, TOS1)
2337 * Low Latency Transactions (AF2x, TOS4)
2338 * Video Streaming (AF4x, AF3x, CS3)
2339 * Bog Standard (CS0 etc.)
2340 * High Throughput (AF1x, TOS2)
2341 * Background Traffic (CS1)
2342 *
2343 * Total 8 traffic classes.
2344 */
2345
2346 struct cake_sched_data *q = qdisc_priv(sch);
2347 u32 mtu = psched_mtu(qdisc_dev(sch));
2348 u64 rate = q->rate_bps;
2349 u32 quantum1 = 256;
2350 u32 quantum2 = 256;
2351 u32 i;
2352
2353 q->tin_cnt = 8;
2354
2355 /* codepoint to class mapping */
2356 q->tin_index = diffserv8;
2357 q->tin_order = normal_order;
2358
2359 /* class characteristics */
2360 for (i = 0; i < q->tin_cnt; i++) {
2361 struct cake_tin_data *b = &q->tins[i];
2362
2363 cake_set_rate(b, rate, mtu, us_to_ns(q->target),
2364 us_to_ns(q->interval));
2365
2366 b->tin_quantum_prio = max_t(u16, 1U, quantum1);
2367 b->tin_quantum_band = max_t(u16, 1U, quantum2);
2368
2369 /* calculate next class's parameters */
2370 rate *= 7;
2371 rate >>= 3;
2372
2373 quantum1 *= 3;
2374 quantum1 >>= 1;
2375
2376 quantum2 *= 7;
2377 quantum2 >>= 3;
2378 }
2379
2380 return 0;
2381}
2382
2383static int cake_config_diffserv4(struct Qdisc *sch)
2384{
2385/* Further pruned list of traffic classes for four-class system:
2386 *
2387 * Latency Sensitive (CS7, CS6, EF, VA, CS5, CS4)
2388 * Streaming Media (AF4x, AF3x, CS3, AF2x, TOS4, CS2, TOS1)
2389 * Best Effort (CS0, AF1x, TOS2, and those not specified)
2390 * Background Traffic (CS1)
2391 *
2392 * Total 4 traffic classes.
2393 */
2394
2395 struct cake_sched_data *q = qdisc_priv(sch);
2396 u32 mtu = psched_mtu(qdisc_dev(sch));
2397 u64 rate = q->rate_bps;
2398 u32 quantum = 1024;
2399
2400 q->tin_cnt = 4;
2401
2402 /* codepoint to class mapping */
2403 q->tin_index = diffserv4;
2404 q->tin_order = bulk_order;
2405
2406 /* class characteristics */
2407 cake_set_rate(&q->tins[0], rate, mtu,
2408 us_to_ns(q->target), us_to_ns(q->interval));
2409 cake_set_rate(&q->tins[1], rate >> 4, mtu,
2410 us_to_ns(q->target), us_to_ns(q->interval));
2411 cake_set_rate(&q->tins[2], rate >> 1, mtu,
2412 us_to_ns(q->target), us_to_ns(q->interval));
2413 cake_set_rate(&q->tins[3], rate >> 2, mtu,
2414 us_to_ns(q->target), us_to_ns(q->interval));
2415
2416 /* priority weights */
2417 q->tins[0].tin_quantum_prio = quantum;
2418 q->tins[1].tin_quantum_prio = quantum >> 4;
2419 q->tins[2].tin_quantum_prio = quantum << 2;
2420 q->tins[3].tin_quantum_prio = quantum << 4;
2421
2422 /* bandwidth-sharing weights */
2423 q->tins[0].tin_quantum_band = quantum;
2424 q->tins[1].tin_quantum_band = quantum >> 4;
2425 q->tins[2].tin_quantum_band = quantum >> 1;
2426 q->tins[3].tin_quantum_band = quantum >> 2;
2427
2428 return 0;
2429}
2430
2431static int cake_config_diffserv3(struct Qdisc *sch)
2432{
2433/* Simplified Diffserv structure with 3 tins.
2434 * Low Priority (CS1)
2435 * Best Effort
2436 * Latency Sensitive (TOS4, VA, EF, CS6, CS7)
2437 */
2438 struct cake_sched_data *q = qdisc_priv(sch);
2439 u32 mtu = psched_mtu(qdisc_dev(sch));
2440 u64 rate = q->rate_bps;
2441 u32 quantum = 1024;
2442
2443 q->tin_cnt = 3;
2444
2445 /* codepoint to class mapping */
2446 q->tin_index = diffserv3;
2447 q->tin_order = bulk_order;
2448
2449 /* class characteristics */
2450 cake_set_rate(&q->tins[0], rate, mtu,
2451 us_to_ns(q->target), us_to_ns(q->interval));
2452 cake_set_rate(&q->tins[1], rate >> 4, mtu,
2453 us_to_ns(q->target), us_to_ns(q->interval));
2454 cake_set_rate(&q->tins[2], rate >> 2, mtu,
2455 us_to_ns(q->target), us_to_ns(q->interval));
2456
2457 /* priority weights */
2458 q->tins[0].tin_quantum_prio = quantum;
2459 q->tins[1].tin_quantum_prio = quantum >> 4;
2460 q->tins[2].tin_quantum_prio = quantum << 4;
2461
2462 /* bandwidth-sharing weights */
2463 q->tins[0].tin_quantum_band = quantum;
2464 q->tins[1].tin_quantum_band = quantum >> 4;
2465 q->tins[2].tin_quantum_band = quantum >> 2;
2466
2467 return 0;
2468}
2469
2470static void cake_reconfigure(struct Qdisc *sch)
2471{
2472 struct cake_sched_data *q = qdisc_priv(sch);
2473 int c, ft;
2474
2475 switch (q->tin_mode) {
2476 case CAKE_DIFFSERV_BESTEFFORT:
2477 ft = cake_config_besteffort(sch);
2478 break;
2479
2480 case CAKE_DIFFSERV_PRECEDENCE:
2481 ft = cake_config_precedence(sch);
2482 break;
2483
2484 case CAKE_DIFFSERV_DIFFSERV8:
2485 ft = cake_config_diffserv8(sch);
2486 break;
2487
2488 case CAKE_DIFFSERV_DIFFSERV4:
2489 ft = cake_config_diffserv4(sch);
2490 break;
2491
2492 case CAKE_DIFFSERV_DIFFSERV3:
2493 default:
2494 ft = cake_config_diffserv3(sch);
2495 break;
2496 }
2497
2498 for (c = q->tin_cnt; c < CAKE_MAX_TINS; c++) {
2499 cake_clear_tin(sch, c);
2500 q->tins[c].cparams.mtu_time = q->tins[ft].cparams.mtu_time;
2501 }
2502
2503 q->rate_ns = q->tins[ft].tin_rate_ns;
2504 q->rate_shft = q->tins[ft].tin_rate_shft;
2505
2506 if (q->buffer_config_limit) {
2507 q->buffer_limit = q->buffer_config_limit;
2508 } else if (q->rate_bps) {
2509 u64 t = q->rate_bps * q->interval;
2510
2511 do_div(t, USEC_PER_SEC / 4);
2512 q->buffer_limit = max_t(u32, t, 4U << 20);
2513 } else {
2514 q->buffer_limit = ~0;
2515 }
2516
2517 sch->flags &= ~TCQ_F_CAN_BYPASS;
2518
2519 q->buffer_limit = min(q->buffer_limit,
2520 max(sch->limit * psched_mtu(qdisc_dev(sch)),
2521 q->buffer_config_limit));
2522}
2523
2524static int cake_change(struct Qdisc *sch, struct nlattr *opt,
2525 struct netlink_ext_ack *extack)
2526{
2527 struct cake_sched_data *q = qdisc_priv(sch);
2528 struct nlattr *tb[TCA_CAKE_MAX + 1];
2529 int err;
2530
2531 if (!opt)
2532 return -EINVAL;
2533
2534 err = nla_parse_nested_deprecated(tb, TCA_CAKE_MAX, opt, cake_policy,
2535 extack);
2536 if (err < 0)
2537 return err;
2538
2539 if (tb[TCA_CAKE_NAT]) {
2540#if IS_ENABLED(CONFIG_NF_CONNTRACK)
2541 q->flow_mode &= ~CAKE_FLOW_NAT_FLAG;
2542 q->flow_mode |= CAKE_FLOW_NAT_FLAG *
2543 !!nla_get_u32(tb[TCA_CAKE_NAT]);
2544#else
2545 NL_SET_ERR_MSG_ATTR(extack, tb[TCA_CAKE_NAT],
2546 "No conntrack support in kernel");
2547 return -EOPNOTSUPP;
2548#endif
2549 }
2550
2551 if (tb[TCA_CAKE_BASE_RATE64])
2552 q->rate_bps = nla_get_u64(tb[TCA_CAKE_BASE_RATE64]);
2553
2554 if (tb[TCA_CAKE_DIFFSERV_MODE])
2555 q->tin_mode = nla_get_u32(tb[TCA_CAKE_DIFFSERV_MODE]);
2556
2557 if (tb[TCA_CAKE_WASH]) {
2558 if (!!nla_get_u32(tb[TCA_CAKE_WASH]))
2559 q->rate_flags |= CAKE_FLAG_WASH;
2560 else
2561 q->rate_flags &= ~CAKE_FLAG_WASH;
2562 }
2563
2564 if (tb[TCA_CAKE_FLOW_MODE])
2565 q->flow_mode = ((q->flow_mode & CAKE_FLOW_NAT_FLAG) |
2566 (nla_get_u32(tb[TCA_CAKE_FLOW_MODE]) &
2567 CAKE_FLOW_MASK));
2568
2569 if (tb[TCA_CAKE_ATM])
2570 q->atm_mode = nla_get_u32(tb[TCA_CAKE_ATM]);
2571
2572 if (tb[TCA_CAKE_OVERHEAD]) {
2573 q->rate_overhead = nla_get_s32(tb[TCA_CAKE_OVERHEAD]);
2574 q->rate_flags |= CAKE_FLAG_OVERHEAD;
2575
2576 q->max_netlen = 0;
2577 q->max_adjlen = 0;
2578 q->min_netlen = ~0;
2579 q->min_adjlen = ~0;
2580 }
2581
2582 if (tb[TCA_CAKE_RAW]) {
2583 q->rate_flags &= ~CAKE_FLAG_OVERHEAD;
2584
2585 q->max_netlen = 0;
2586 q->max_adjlen = 0;
2587 q->min_netlen = ~0;
2588 q->min_adjlen = ~0;
2589 }
2590
2591 if (tb[TCA_CAKE_MPU])
2592 q->rate_mpu = nla_get_u32(tb[TCA_CAKE_MPU]);
2593
2594 if (tb[TCA_CAKE_RTT]) {
2595 q->interval = nla_get_u32(tb[TCA_CAKE_RTT]);
2596
2597 if (!q->interval)
2598 q->interval = 1;
2599 }
2600
2601 if (tb[TCA_CAKE_TARGET]) {
2602 q->target = nla_get_u32(tb[TCA_CAKE_TARGET]);
2603
2604 if (!q->target)
2605 q->target = 1;
2606 }
2607
2608 if (tb[TCA_CAKE_AUTORATE]) {
2609 if (!!nla_get_u32(tb[TCA_CAKE_AUTORATE]))
2610 q->rate_flags |= CAKE_FLAG_AUTORATE_INGRESS;
2611 else
2612 q->rate_flags &= ~CAKE_FLAG_AUTORATE_INGRESS;
2613 }
2614
2615 if (tb[TCA_CAKE_INGRESS]) {
2616 if (!!nla_get_u32(tb[TCA_CAKE_INGRESS]))
2617 q->rate_flags |= CAKE_FLAG_INGRESS;
2618 else
2619 q->rate_flags &= ~CAKE_FLAG_INGRESS;
2620 }
2621
2622 if (tb[TCA_CAKE_ACK_FILTER])
2623 q->ack_filter = nla_get_u32(tb[TCA_CAKE_ACK_FILTER]);
2624
2625 if (tb[TCA_CAKE_MEMORY])
2626 q->buffer_config_limit = nla_get_u32(tb[TCA_CAKE_MEMORY]);
2627
2628 if (tb[TCA_CAKE_SPLIT_GSO]) {
2629 if (!!nla_get_u32(tb[TCA_CAKE_SPLIT_GSO]))
2630 q->rate_flags |= CAKE_FLAG_SPLIT_GSO;
2631 else
2632 q->rate_flags &= ~CAKE_FLAG_SPLIT_GSO;
2633 }
2634
2635 if (tb[TCA_CAKE_FWMARK]) {
2636 q->fwmark_mask = nla_get_u32(tb[TCA_CAKE_FWMARK]);
2637 q->fwmark_shft = q->fwmark_mask ? __ffs(q->fwmark_mask) : 0;
2638 }
2639
2640 if (q->tins) {
2641 sch_tree_lock(sch);
2642 cake_reconfigure(sch);
2643 sch_tree_unlock(sch);
2644 }
2645
2646 return 0;
2647}
2648
2649static void cake_destroy(struct Qdisc *sch)
2650{
2651 struct cake_sched_data *q = qdisc_priv(sch);
2652
2653 qdisc_watchdog_cancel(&q->watchdog);
2654 tcf_block_put(q->block);
2655 kvfree(q->tins);
2656}
2657
2658static int cake_init(struct Qdisc *sch, struct nlattr *opt,
2659 struct netlink_ext_ack *extack)
2660{
2661 struct cake_sched_data *q = qdisc_priv(sch);
2662 int i, j, err;
2663
2664 sch->limit = 10240;
2665 q->tin_mode = CAKE_DIFFSERV_DIFFSERV3;
2666 q->flow_mode = CAKE_FLOW_TRIPLE;
2667
2668 q->rate_bps = 0; /* unlimited by default */
2669
2670 q->interval = 100000; /* 100ms default */
2671 q->target = 5000; /* 5ms: codel RFC argues
2672 * for 5 to 10% of interval
2673 */
2674 q->rate_flags |= CAKE_FLAG_SPLIT_GSO;
2675 q->cur_tin = 0;
2676 q->cur_flow = 0;
2677
2678 qdisc_watchdog_init(&q->watchdog, sch);
2679
2680 if (opt) {
2681 int err = cake_change(sch, opt, extack);
2682
2683 if (err)
2684 return err;
2685 }
2686
2687 err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
2688 if (err)
2689 return err;
2690
2691 quantum_div[0] = ~0;
2692 for (i = 1; i <= CAKE_QUEUES; i++)
2693 quantum_div[i] = 65535 / i;
2694
2695 q->tins = kvcalloc(CAKE_MAX_TINS, sizeof(struct cake_tin_data),
2696 GFP_KERNEL);
2697 if (!q->tins)
2698 goto nomem;
2699
2700 for (i = 0; i < CAKE_MAX_TINS; i++) {
2701 struct cake_tin_data *b = q->tins + i;
2702
2703 INIT_LIST_HEAD(&b->new_flows);
2704 INIT_LIST_HEAD(&b->old_flows);
2705 INIT_LIST_HEAD(&b->decaying_flows);
2706 b->sparse_flow_count = 0;
2707 b->bulk_flow_count = 0;
2708 b->decaying_flow_count = 0;
2709
2710 for (j = 0; j < CAKE_QUEUES; j++) {
2711 struct cake_flow *flow = b->flows + j;
2712 u32 k = j * CAKE_MAX_TINS + i;
2713
2714 INIT_LIST_HEAD(&flow->flowchain);
2715 cobalt_vars_init(&flow->cvars);
2716
2717 q->overflow_heap[k].t = i;
2718 q->overflow_heap[k].b = j;
2719 b->overflow_idx[j] = k;
2720 }
2721 }
2722
2723 cake_reconfigure(sch);
2724 q->avg_peak_bandwidth = q->rate_bps;
2725 q->min_netlen = ~0;
2726 q->min_adjlen = ~0;
2727 return 0;
2728
2729nomem:
2730 cake_destroy(sch);
2731 return -ENOMEM;
2732}
2733
2734static int cake_dump(struct Qdisc *sch, struct sk_buff *skb)
2735{
2736 struct cake_sched_data *q = qdisc_priv(sch);
2737 struct nlattr *opts;
2738
2739 opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
2740 if (!opts)
2741 goto nla_put_failure;
2742
2743 if (nla_put_u64_64bit(skb, TCA_CAKE_BASE_RATE64, q->rate_bps,
2744 TCA_CAKE_PAD))
2745 goto nla_put_failure;
2746
2747 if (nla_put_u32(skb, TCA_CAKE_FLOW_MODE,
2748 q->flow_mode & CAKE_FLOW_MASK))
2749 goto nla_put_failure;
2750
2751 if (nla_put_u32(skb, TCA_CAKE_RTT, q->interval))
2752 goto nla_put_failure;
2753
2754 if (nla_put_u32(skb, TCA_CAKE_TARGET, q->target))
2755 goto nla_put_failure;
2756
2757 if (nla_put_u32(skb, TCA_CAKE_MEMORY, q->buffer_config_limit))
2758 goto nla_put_failure;
2759
2760 if (nla_put_u32(skb, TCA_CAKE_AUTORATE,
2761 !!(q->rate_flags & CAKE_FLAG_AUTORATE_INGRESS)))
2762 goto nla_put_failure;
2763
2764 if (nla_put_u32(skb, TCA_CAKE_INGRESS,
2765 !!(q->rate_flags & CAKE_FLAG_INGRESS)))
2766 goto nla_put_failure;
2767
2768 if (nla_put_u32(skb, TCA_CAKE_ACK_FILTER, q->ack_filter))
2769 goto nla_put_failure;
2770
2771 if (nla_put_u32(skb, TCA_CAKE_NAT,
2772 !!(q->flow_mode & CAKE_FLOW_NAT_FLAG)))
2773 goto nla_put_failure;
2774
2775 if (nla_put_u32(skb, TCA_CAKE_DIFFSERV_MODE, q->tin_mode))
2776 goto nla_put_failure;
2777
2778 if (nla_put_u32(skb, TCA_CAKE_WASH,
2779 !!(q->rate_flags & CAKE_FLAG_WASH)))
2780 goto nla_put_failure;
2781
2782 if (nla_put_u32(skb, TCA_CAKE_OVERHEAD, q->rate_overhead))
2783 goto nla_put_failure;
2784
2785 if (!(q->rate_flags & CAKE_FLAG_OVERHEAD))
2786 if (nla_put_u32(skb, TCA_CAKE_RAW, 0))
2787 goto nla_put_failure;
2788
2789 if (nla_put_u32(skb, TCA_CAKE_ATM, q->atm_mode))
2790 goto nla_put_failure;
2791
2792 if (nla_put_u32(skb, TCA_CAKE_MPU, q->rate_mpu))
2793 goto nla_put_failure;
2794
2795 if (nla_put_u32(skb, TCA_CAKE_SPLIT_GSO,
2796 !!(q->rate_flags & CAKE_FLAG_SPLIT_GSO)))
2797 goto nla_put_failure;
2798
2799 if (nla_put_u32(skb, TCA_CAKE_FWMARK, q->fwmark_mask))
2800 goto nla_put_failure;
2801
2802 return nla_nest_end(skb, opts);
2803
2804nla_put_failure:
2805 return -1;
2806}
2807
2808static int cake_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
2809{
2810 struct nlattr *stats = nla_nest_start_noflag(d->skb, TCA_STATS_APP);
2811 struct cake_sched_data *q = qdisc_priv(sch);
2812 struct nlattr *tstats, *ts;
2813 int i;
2814
2815 if (!stats)
2816 return -1;
2817
2818#define PUT_STAT_U32(attr, data) do { \
2819 if (nla_put_u32(d->skb, TCA_CAKE_STATS_ ## attr, data)) \
2820 goto nla_put_failure; \
2821 } while (0)
2822#define PUT_STAT_U64(attr, data) do { \
2823 if (nla_put_u64_64bit(d->skb, TCA_CAKE_STATS_ ## attr, \
2824 data, TCA_CAKE_STATS_PAD)) \
2825 goto nla_put_failure; \
2826 } while (0)
2827
2828 PUT_STAT_U64(CAPACITY_ESTIMATE64, q->avg_peak_bandwidth);
2829 PUT_STAT_U32(MEMORY_LIMIT, q->buffer_limit);
2830 PUT_STAT_U32(MEMORY_USED, q->buffer_max_used);
2831 PUT_STAT_U32(AVG_NETOFF, ((q->avg_netoff + 0x8000) >> 16));
2832 PUT_STAT_U32(MAX_NETLEN, q->max_netlen);
2833 PUT_STAT_U32(MAX_ADJLEN, q->max_adjlen);
2834 PUT_STAT_U32(MIN_NETLEN, q->min_netlen);
2835 PUT_STAT_U32(MIN_ADJLEN, q->min_adjlen);
2836
2837#undef PUT_STAT_U32
2838#undef PUT_STAT_U64
2839
2840 tstats = nla_nest_start_noflag(d->skb, TCA_CAKE_STATS_TIN_STATS);
2841 if (!tstats)
2842 goto nla_put_failure;
2843
2844#define PUT_TSTAT_U32(attr, data) do { \
2845 if (nla_put_u32(d->skb, TCA_CAKE_TIN_STATS_ ## attr, data)) \
2846 goto nla_put_failure; \
2847 } while (0)
2848#define PUT_TSTAT_U64(attr, data) do { \
2849 if (nla_put_u64_64bit(d->skb, TCA_CAKE_TIN_STATS_ ## attr, \
2850 data, TCA_CAKE_TIN_STATS_PAD)) \
2851 goto nla_put_failure; \
2852 } while (0)
2853
2854 for (i = 0; i < q->tin_cnt; i++) {
2855 struct cake_tin_data *b = &q->tins[q->tin_order[i]];
2856
2857 ts = nla_nest_start_noflag(d->skb, i + 1);
2858 if (!ts)
2859 goto nla_put_failure;
2860
2861 PUT_TSTAT_U64(THRESHOLD_RATE64, b->tin_rate_bps);
2862 PUT_TSTAT_U64(SENT_BYTES64, b->bytes);
2863 PUT_TSTAT_U32(BACKLOG_BYTES, b->tin_backlog);
2864
2865 PUT_TSTAT_U32(TARGET_US,
2866 ktime_to_us(ns_to_ktime(b->cparams.target)));
2867 PUT_TSTAT_U32(INTERVAL_US,
2868 ktime_to_us(ns_to_ktime(b->cparams.interval)));
2869
2870 PUT_TSTAT_U32(SENT_PACKETS, b->packets);
2871 PUT_TSTAT_U32(DROPPED_PACKETS, b->tin_dropped);
2872 PUT_TSTAT_U32(ECN_MARKED_PACKETS, b->tin_ecn_mark);
2873 PUT_TSTAT_U32(ACKS_DROPPED_PACKETS, b->ack_drops);
2874
2875 PUT_TSTAT_U32(PEAK_DELAY_US,
2876 ktime_to_us(ns_to_ktime(b->peak_delay)));
2877 PUT_TSTAT_U32(AVG_DELAY_US,
2878 ktime_to_us(ns_to_ktime(b->avge_delay)));
2879 PUT_TSTAT_U32(BASE_DELAY_US,
2880 ktime_to_us(ns_to_ktime(b->base_delay)));
2881
2882 PUT_TSTAT_U32(WAY_INDIRECT_HITS, b->way_hits);
2883 PUT_TSTAT_U32(WAY_MISSES, b->way_misses);
2884 PUT_TSTAT_U32(WAY_COLLISIONS, b->way_collisions);
2885
2886 PUT_TSTAT_U32(SPARSE_FLOWS, b->sparse_flow_count +
2887 b->decaying_flow_count);
2888 PUT_TSTAT_U32(BULK_FLOWS, b->bulk_flow_count);
2889 PUT_TSTAT_U32(UNRESPONSIVE_FLOWS, b->unresponsive_flow_count);
2890 PUT_TSTAT_U32(MAX_SKBLEN, b->max_skblen);
2891
2892 PUT_TSTAT_U32(FLOW_QUANTUM, b->flow_quantum);
2893 nla_nest_end(d->skb, ts);
2894 }
2895
2896#undef PUT_TSTAT_U32
2897#undef PUT_TSTAT_U64
2898
2899 nla_nest_end(d->skb, tstats);
2900 return nla_nest_end(d->skb, stats);
2901
2902nla_put_failure:
2903 nla_nest_cancel(d->skb, stats);
2904 return -1;
2905}
2906
2907static struct Qdisc *cake_leaf(struct Qdisc *sch, unsigned long arg)
2908{
2909 return NULL;
2910}
2911
2912static unsigned long cake_find(struct Qdisc *sch, u32 classid)
2913{
2914 return 0;
2915}
2916
2917static unsigned long cake_bind(struct Qdisc *sch, unsigned long parent,
2918 u32 classid)
2919{
2920 return 0;
2921}
2922
2923static void cake_unbind(struct Qdisc *q, unsigned long cl)
2924{
2925}
2926
2927static struct tcf_block *cake_tcf_block(struct Qdisc *sch, unsigned long cl,
2928 struct netlink_ext_ack *extack)
2929{
2930 struct cake_sched_data *q = qdisc_priv(sch);
2931
2932 if (cl)
2933 return NULL;
2934 return q->block;
2935}
2936
2937static int cake_dump_class(struct Qdisc *sch, unsigned long cl,
2938 struct sk_buff *skb, struct tcmsg *tcm)
2939{
2940 tcm->tcm_handle |= TC_H_MIN(cl);
2941 return 0;
2942}
2943
2944static int cake_dump_class_stats(struct Qdisc *sch, unsigned long cl,
2945 struct gnet_dump *d)
2946{
2947 struct cake_sched_data *q = qdisc_priv(sch);
2948 const struct cake_flow *flow = NULL;
2949 struct gnet_stats_queue qs = { 0 };
2950 struct nlattr *stats;
2951 u32 idx = cl - 1;
2952
2953 if (idx < CAKE_QUEUES * q->tin_cnt) {
2954 const struct cake_tin_data *b = \
2955 &q->tins[q->tin_order[idx / CAKE_QUEUES]];
2956 const struct sk_buff *skb;
2957
2958 flow = &b->flows[idx % CAKE_QUEUES];
2959
2960 if (flow->head) {
2961 sch_tree_lock(sch);
2962 skb = flow->head;
2963 while (skb) {
2964 qs.qlen++;
2965 skb = skb->next;
2966 }
2967 sch_tree_unlock(sch);
2968 }
2969 qs.backlog = b->backlogs[idx % CAKE_QUEUES];
2970 qs.drops = flow->dropped;
2971 }
2972 if (gnet_stats_copy_queue(d, NULL, &qs, qs.qlen) < 0)
2973 return -1;
2974 if (flow) {
2975 ktime_t now = ktime_get();
2976
2977 stats = nla_nest_start_noflag(d->skb, TCA_STATS_APP);
2978 if (!stats)
2979 return -1;
2980
2981#define PUT_STAT_U32(attr, data) do { \
2982 if (nla_put_u32(d->skb, TCA_CAKE_STATS_ ## attr, data)) \
2983 goto nla_put_failure; \
2984 } while (0)
2985#define PUT_STAT_S32(attr, data) do { \
2986 if (nla_put_s32(d->skb, TCA_CAKE_STATS_ ## attr, data)) \
2987 goto nla_put_failure; \
2988 } while (0)
2989
2990 PUT_STAT_S32(DEFICIT, flow->deficit);
2991 PUT_STAT_U32(DROPPING, flow->cvars.dropping);
2992 PUT_STAT_U32(COBALT_COUNT, flow->cvars.count);
2993 PUT_STAT_U32(P_DROP, flow->cvars.p_drop);
2994 if (flow->cvars.p_drop) {
2995 PUT_STAT_S32(BLUE_TIMER_US,
2996 ktime_to_us(
2997 ktime_sub(now,
2998 flow->cvars.blue_timer)));
2999 }
3000 if (flow->cvars.dropping) {
3001 PUT_STAT_S32(DROP_NEXT_US,
3002 ktime_to_us(
3003 ktime_sub(now,
3004 flow->cvars.drop_next)));
3005 }
3006
3007 if (nla_nest_end(d->skb, stats) < 0)
3008 return -1;
3009 }
3010
3011 return 0;
3012
3013nla_put_failure:
3014 nla_nest_cancel(d->skb, stats);
3015 return -1;
3016}
3017
3018static void cake_walk(struct Qdisc *sch, struct qdisc_walker *arg)
3019{
3020 struct cake_sched_data *q = qdisc_priv(sch);
3021 unsigned int i, j;
3022
3023 if (arg->stop)
3024 return;
3025
3026 for (i = 0; i < q->tin_cnt; i++) {
3027 struct cake_tin_data *b = &q->tins[q->tin_order[i]];
3028
3029 for (j = 0; j < CAKE_QUEUES; j++) {
3030 if (list_empty(&b->flows[j].flowchain) ||
3031 arg->count < arg->skip) {
3032 arg->count++;
3033 continue;
3034 }
3035 if (arg->fn(sch, i * CAKE_QUEUES + j + 1, arg) < 0) {
3036 arg->stop = 1;
3037 break;
3038 }
3039 arg->count++;
3040 }
3041 }
3042}
3043
3044static const struct Qdisc_class_ops cake_class_ops = {
3045 .leaf = cake_leaf,
3046 .find = cake_find,
3047 .tcf_block = cake_tcf_block,
3048 .bind_tcf = cake_bind,
3049 .unbind_tcf = cake_unbind,
3050 .dump = cake_dump_class,
3051 .dump_stats = cake_dump_class_stats,
3052 .walk = cake_walk,
3053};
3054
3055static struct Qdisc_ops cake_qdisc_ops __read_mostly = {
3056 .cl_ops = &cake_class_ops,
3057 .id = "cake",
3058 .priv_size = sizeof(struct cake_sched_data),
3059 .enqueue = cake_enqueue,
3060 .dequeue = cake_dequeue,
3061 .peek = qdisc_peek_dequeued,
3062 .init = cake_init,
3063 .reset = cake_reset,
3064 .destroy = cake_destroy,
3065 .change = cake_change,
3066 .dump = cake_dump,
3067 .dump_stats = cake_dump_stats,
3068 .owner = THIS_MODULE,
3069};
3070
3071static int __init cake_module_init(void)
3072{
3073 return register_qdisc(&cake_qdisc_ops);
3074}
3075
3076static void __exit cake_module_exit(void)
3077{
3078 unregister_qdisc(&cake_qdisc_ops);
3079}
3080
3081module_init(cake_module_init)
3082module_exit(cake_module_exit)
3083MODULE_AUTHOR("Jonathan Morton");
3084MODULE_LICENSE("Dual BSD/GPL");
3085MODULE_DESCRIPTION("The CAKE shaper.");