1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * net/sched/sch_htb.c Hierarchical token bucket, feed tree version
4 *
5 * Authors: Martin Devera, <devik@cdi.cz>
6 *
7 * Credits (in time order) for older HTB versions:
8 * Stef Coene <stef.coene@docum.org>
9 * HTB support at LARTC mailing list
10 * Ondrej Kraus, <krauso@barr.cz>
11 * found missing INIT_QDISC(htb)
12 * Vladimir Smelhaus, Aamer Akhter, Bert Hubert
13 * helped a lot to locate nasty class stall bug
14 * Andi Kleen, Jamal Hadi, Bert Hubert
15 * code review and helpful comments on shaping
16 * Tomasz Wrona, <tw@eter.tym.pl>
17 * created test case so that I was able to fix nasty bug
18 * Wilfried Weissmann
19 * spotted bug in dequeue code and helped with fix
20 * Jiri Fojtasek
21 * fixed requeue routine
22 * and many others. thanks.
23 */
24 #include <linux/module.h>
25 #include <linux/moduleparam.h>
26 #include <linux/types.h>
27 #include <linux/kernel.h>
28 #include <linux/string.h>
29 #include <linux/errno.h>
30 #include <linux/skbuff.h>
31 #include <linux/list.h>
32 #include <linux/compiler.h>
33 #include <linux/rbtree.h>
34 #include <linux/workqueue.h>
35 #include <linux/slab.h>
36 #include <net/netlink.h>
37 #include <net/sch_generic.h>
38 #include <net/pkt_sched.h>
39 #include <net/pkt_cls.h>
40
41 /* HTB algorithm.
42 Author: devik@cdi.cz
43 ========================================================================
44 HTB is like TBF with multiple classes. It is also similar to CBQ because
45 it allows to assign priority to each class in hierarchy.
46 In fact it is another implementation of Floyd's formal sharing.
47
48 Levels:
49 Each class is assigned level. Leaf has ALWAYS level 0 and root
50 classes have level TC_HTB_MAXDEPTH-1. Interior nodes has level
51 one less than their parent.
52 */
53
54 static int htb_hysteresis __read_mostly = 0; /* whether to use mode hysteresis for speedup */
55 #define HTB_VER 0x30011 /* major must be matched with number suplied by TC as version */
56
57 #if HTB_VER >> 16 != TC_HTB_PROTOVER
58 #error "Mismatched sch_htb.c and pkt_sch.h"
59 #endif
60
61 /* Module parameter and sysfs export */
62 module_param (htb_hysteresis, int, 0640);
63 MODULE_PARM_DESC(htb_hysteresis, "Hysteresis mode, less CPU load, less accurate");
64
65 static int htb_rate_est = 0; /* htb classes have a default rate estimator */
66 module_param(htb_rate_est, int, 0640);
67 MODULE_PARM_DESC(htb_rate_est, "setup a default rate estimator (4sec 16sec) for htb classes");
68
69 /* used internaly to keep status of single class */
70 enum htb_cmode {
71 HTB_CANT_SEND, /* class can't send and can't borrow */
72 HTB_MAY_BORROW, /* class can't send but may borrow */
73 HTB_CAN_SEND /* class can send */
74 };
75
76 struct htb_prio {
77 union {
78 struct rb_root row;
79 struct rb_root feed;
80 };
81 struct rb_node *ptr;
82 /* When class changes from state 1->2 and disconnects from
83 * parent's feed then we lost ptr value and start from the
84 * first child again. Here we store classid of the
85 * last valid ptr (used when ptr is NULL).
86 */
87 u32 last_ptr_id;
88 };
89
90 /* interior & leaf nodes; props specific to leaves are marked L:
91 * To reduce false sharing, place mostly read fields at beginning,
92 * and mostly written ones at the end.
93 */
94 struct htb_class {
95 struct Qdisc_class_common common;
96 struct psched_ratecfg rate;
97 struct psched_ratecfg ceil;
98 s64 buffer, cbuffer;/* token bucket depth/rate */
99 s64 mbuffer; /* max wait time */
100 u32 prio; /* these two are used only by leaves... */
101 int quantum; /* but stored for parent-to-leaf return */
102
103 struct tcf_proto __rcu *filter_list; /* class attached filters */
104 struct tcf_block *block;
105 int filter_cnt;
106
107 int level; /* our level (see above) */
108 unsigned int children;
109 struct htb_class *parent; /* parent class */
110
111 struct net_rate_estimator __rcu *rate_est;
112
113 /*
114 * Written often fields
115 */
116 struct gnet_stats_basic_packed bstats;
117 struct gnet_stats_basic_packed bstats_bias;
118 struct tc_htb_xstats xstats; /* our special stats */
119
120 /* token bucket parameters */
121 s64 tokens, ctokens;/* current number of tokens */
122 s64 t_c; /* checkpoint time */
123
124 union {
125 struct htb_class_leaf {
126 int deficit[TC_HTB_MAXDEPTH];
127 struct Qdisc *q;
128 } leaf;
129 struct htb_class_inner {
130 struct htb_prio clprio[TC_HTB_NUMPRIO];
131 } inner;
132 };
133 s64 pq_key;
134
135 int prio_activity; /* for which prios are we active */
136 enum htb_cmode cmode; /* current mode of the class */
137 struct rb_node pq_node; /* node for event queue */
138 struct rb_node node[TC_HTB_NUMPRIO]; /* node for self or feed tree */
139
140 unsigned int drops ____cacheline_aligned_in_smp;
141 unsigned int overlimits;
142 };
143
144 struct htb_level {
145 struct rb_root wait_pq;
146 struct htb_prio hprio[TC_HTB_NUMPRIO];
147 };
148
149 struct htb_sched {
150 struct Qdisc_class_hash clhash;
151 int defcls; /* class where unclassified flows go to */
152 int rate2quantum; /* quant = rate / rate2quantum */
153
154 /* filters for qdisc itself */
155 struct tcf_proto __rcu *filter_list;
156 struct tcf_block *block;
157
158 #define HTB_WARN_TOOMANYEVENTS 0x1
159 unsigned int warned; /* only one warning */
160 int direct_qlen;
161 struct work_struct work;
162
163 /* non shaped skbs; let them go directly thru */
164 struct qdisc_skb_head direct_queue;
165 u32 direct_pkts;
166 u32 overlimits;
167
168 struct qdisc_watchdog watchdog;
169
170 s64 now; /* cached dequeue time */
171
172 /* time of nearest event per level (row) */
173 s64 near_ev_cache[TC_HTB_MAXDEPTH];
174
175 int row_mask[TC_HTB_MAXDEPTH];
176
177 struct htb_level hlevel[TC_HTB_MAXDEPTH];
178
179 struct Qdisc **direct_qdiscs;
180 unsigned int num_direct_qdiscs;
181
182 bool offload;
183 };
184
185 /* find class in global hash table using given handle */
htb_find(u32 handle,struct Qdisc * sch)186 static inline struct htb_class *htb_find(u32 handle, struct Qdisc *sch)
187 {
188 struct htb_sched *q = qdisc_priv(sch);
189 struct Qdisc_class_common *clc;
190
191 clc = qdisc_class_find(&q->clhash, handle);
192 if (clc == NULL)
193 return NULL;
194 return container_of(clc, struct htb_class, common);
195 }
196
htb_search(struct Qdisc * sch,u32 handle)197 static unsigned long htb_search(struct Qdisc *sch, u32 handle)
198 {
199 return (unsigned long)htb_find(handle, sch);
200 }
201 /**
202 * htb_classify - classify a packet into class
203 *
204 * It returns NULL if the packet should be dropped or -1 if the packet
205 * should be passed directly thru. In all other cases leaf class is returned.
206 * We allow direct class selection by classid in priority. The we examine
207 * filters in qdisc and in inner nodes (if higher filter points to the inner
208 * node). If we end up with classid MAJOR:0 we enqueue the skb into special
209 * internal fifo (direct). These packets then go directly thru. If we still
210 * have no valid leaf we try to use MAJOR:default leaf. It still unsuccessful
211 * then finish and return direct queue.
212 */
213 #define HTB_DIRECT ((struct htb_class *)-1L)
214
htb_classify(struct sk_buff * skb,struct Qdisc * sch,int * qerr)215 static struct htb_class *htb_classify(struct sk_buff *skb, struct Qdisc *sch,
216 int *qerr)
217 {
218 struct htb_sched *q = qdisc_priv(sch);
219 struct htb_class *cl;
220 struct tcf_result res;
221 struct tcf_proto *tcf;
222 int result;
223
224 /* allow to select class by setting skb->priority to valid classid;
225 * note that nfmark can be used too by attaching filter fw with no
226 * rules in it
227 */
228 if (skb->priority == sch->handle)
229 return HTB_DIRECT; /* X:0 (direct flow) selected */
230 cl = htb_find(skb->priority, sch);
231 if (cl) {
232 if (cl->level == 0)
233 return cl;
234 /* Start with inner filter chain if a non-leaf class is selected */
235 tcf = rcu_dereference_bh(cl->filter_list);
236 } else {
237 tcf = rcu_dereference_bh(q->filter_list);
238 }
239
240 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
241 while (tcf && (result = tcf_classify(skb, tcf, &res, false)) >= 0) {
242 #ifdef CONFIG_NET_CLS_ACT
243 switch (result) {
244 case TC_ACT_QUEUED:
245 case TC_ACT_STOLEN:
246 case TC_ACT_TRAP:
247 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
248 fallthrough;
249 case TC_ACT_SHOT:
250 return NULL;
251 }
252 #endif
253 cl = (void *)res.class;
254 if (!cl) {
255 if (res.classid == sch->handle)
256 return HTB_DIRECT; /* X:0 (direct flow) */
257 cl = htb_find(res.classid, sch);
258 if (!cl)
259 break; /* filter selected invalid classid */
260 }
261 if (!cl->level)
262 return cl; /* we hit leaf; return it */
263
264 /* we have got inner class; apply inner filter chain */
265 tcf = rcu_dereference_bh(cl->filter_list);
266 }
267 /* classification failed; try to use default class */
268 cl = htb_find(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch);
269 if (!cl || cl->level)
270 return HTB_DIRECT; /* bad default .. this is safe bet */
271 return cl;
272 }
273
274 /**
275 * htb_add_to_id_tree - adds class to the round robin list
276 *
277 * Routine adds class to the list (actually tree) sorted by classid.
278 * Make sure that class is not already on such list for given prio.
279 */
htb_add_to_id_tree(struct rb_root * root,struct htb_class * cl,int prio)280 static void htb_add_to_id_tree(struct rb_root *root,
281 struct htb_class *cl, int prio)
282 {
283 struct rb_node **p = &root->rb_node, *parent = NULL;
284
285 while (*p) {
286 struct htb_class *c;
287 parent = *p;
288 c = rb_entry(parent, struct htb_class, node[prio]);
289
290 if (cl->common.classid > c->common.classid)
291 p = &parent->rb_right;
292 else
293 p = &parent->rb_left;
294 }
295 rb_link_node(&cl->node[prio], parent, p);
296 rb_insert_color(&cl->node[prio], root);
297 }
298
299 /**
300 * htb_add_to_wait_tree - adds class to the event queue with delay
301 *
302 * The class is added to priority event queue to indicate that class will
303 * change its mode in cl->pq_key microseconds. Make sure that class is not
304 * already in the queue.
305 */
htb_add_to_wait_tree(struct htb_sched * q,struct htb_class * cl,s64 delay)306 static void htb_add_to_wait_tree(struct htb_sched *q,
307 struct htb_class *cl, s64 delay)
308 {
309 struct rb_node **p = &q->hlevel[cl->level].wait_pq.rb_node, *parent = NULL;
310
311 cl->pq_key = q->now + delay;
312 if (cl->pq_key == q->now)
313 cl->pq_key++;
314
315 /* update the nearest event cache */
316 if (q->near_ev_cache[cl->level] > cl->pq_key)
317 q->near_ev_cache[cl->level] = cl->pq_key;
318
319 while (*p) {
320 struct htb_class *c;
321 parent = *p;
322 c = rb_entry(parent, struct htb_class, pq_node);
323 if (cl->pq_key >= c->pq_key)
324 p = &parent->rb_right;
325 else
326 p = &parent->rb_left;
327 }
328 rb_link_node(&cl->pq_node, parent, p);
329 rb_insert_color(&cl->pq_node, &q->hlevel[cl->level].wait_pq);
330 }
331
332 /**
333 * htb_next_rb_node - finds next node in binary tree
334 *
335 * When we are past last key we return NULL.
336 * Average complexity is 2 steps per call.
337 */
htb_next_rb_node(struct rb_node ** n)338 static inline void htb_next_rb_node(struct rb_node **n)
339 {
340 *n = rb_next(*n);
341 }
342
343 /**
344 * htb_add_class_to_row - add class to its row
345 *
346 * The class is added to row at priorities marked in mask.
347 * It does nothing if mask == 0.
348 */
htb_add_class_to_row(struct htb_sched * q,struct htb_class * cl,int mask)349 static inline void htb_add_class_to_row(struct htb_sched *q,
350 struct htb_class *cl, int mask)
351 {
352 q->row_mask[cl->level] |= mask;
353 while (mask) {
354 int prio = ffz(~mask);
355 mask &= ~(1 << prio);
356 htb_add_to_id_tree(&q->hlevel[cl->level].hprio[prio].row, cl, prio);
357 }
358 }
359
360 /* If this triggers, it is a bug in this code, but it need not be fatal */
htb_safe_rb_erase(struct rb_node * rb,struct rb_root * root)361 static void htb_safe_rb_erase(struct rb_node *rb, struct rb_root *root)
362 {
363 if (RB_EMPTY_NODE(rb)) {
364 WARN_ON(1);
365 } else {
366 rb_erase(rb, root);
367 RB_CLEAR_NODE(rb);
368 }
369 }
370
371
372 /**
373 * htb_remove_class_from_row - removes class from its row
374 *
375 * The class is removed from row at priorities marked in mask.
376 * It does nothing if mask == 0.
377 */
htb_remove_class_from_row(struct htb_sched * q,struct htb_class * cl,int mask)378 static inline void htb_remove_class_from_row(struct htb_sched *q,
379 struct htb_class *cl, int mask)
380 {
381 int m = 0;
382 struct htb_level *hlevel = &q->hlevel[cl->level];
383
384 while (mask) {
385 int prio = ffz(~mask);
386 struct htb_prio *hprio = &hlevel->hprio[prio];
387
388 mask &= ~(1 << prio);
389 if (hprio->ptr == cl->node + prio)
390 htb_next_rb_node(&hprio->ptr);
391
392 htb_safe_rb_erase(cl->node + prio, &hprio->row);
393 if (!hprio->row.rb_node)
394 m |= 1 << prio;
395 }
396 q->row_mask[cl->level] &= ~m;
397 }
398
399 /**
400 * htb_activate_prios - creates active classe's feed chain
401 *
402 * The class is connected to ancestors and/or appropriate rows
403 * for priorities it is participating on. cl->cmode must be new
404 * (activated) mode. It does nothing if cl->prio_activity == 0.
405 */
htb_activate_prios(struct htb_sched * q,struct htb_class * cl)406 static void htb_activate_prios(struct htb_sched *q, struct htb_class *cl)
407 {
408 struct htb_class *p = cl->parent;
409 long m, mask = cl->prio_activity;
410
411 while (cl->cmode == HTB_MAY_BORROW && p && mask) {
412 m = mask;
413 while (m) {
414 int prio = ffz(~m);
415 m &= ~(1 << prio);
416
417 if (p->inner.clprio[prio].feed.rb_node)
418 /* parent already has its feed in use so that
419 * reset bit in mask as parent is already ok
420 */
421 mask &= ~(1 << prio);
422
423 htb_add_to_id_tree(&p->inner.clprio[prio].feed, cl, prio);
424 }
425 p->prio_activity |= mask;
426 cl = p;
427 p = cl->parent;
428
429 }
430 if (cl->cmode == HTB_CAN_SEND && mask)
431 htb_add_class_to_row(q, cl, mask);
432 }
433
434 /**
435 * htb_deactivate_prios - remove class from feed chain
436 *
437 * cl->cmode must represent old mode (before deactivation). It does
438 * nothing if cl->prio_activity == 0. Class is removed from all feed
439 * chains and rows.
440 */
htb_deactivate_prios(struct htb_sched * q,struct htb_class * cl)441 static void htb_deactivate_prios(struct htb_sched *q, struct htb_class *cl)
442 {
443 struct htb_class *p = cl->parent;
444 long m, mask = cl->prio_activity;
445
446 while (cl->cmode == HTB_MAY_BORROW && p && mask) {
447 m = mask;
448 mask = 0;
449 while (m) {
450 int prio = ffz(~m);
451 m &= ~(1 << prio);
452
453 if (p->inner.clprio[prio].ptr == cl->node + prio) {
454 /* we are removing child which is pointed to from
455 * parent feed - forget the pointer but remember
456 * classid
457 */
458 p->inner.clprio[prio].last_ptr_id = cl->common.classid;
459 p->inner.clprio[prio].ptr = NULL;
460 }
461
462 htb_safe_rb_erase(cl->node + prio,
463 &p->inner.clprio[prio].feed);
464
465 if (!p->inner.clprio[prio].feed.rb_node)
466 mask |= 1 << prio;
467 }
468
469 p->prio_activity &= ~mask;
470 cl = p;
471 p = cl->parent;
472
473 }
474 if (cl->cmode == HTB_CAN_SEND && mask)
475 htb_remove_class_from_row(q, cl, mask);
476 }
477
htb_lowater(const struct htb_class * cl)478 static inline s64 htb_lowater(const struct htb_class *cl)
479 {
480 if (htb_hysteresis)
481 return cl->cmode != HTB_CANT_SEND ? -cl->cbuffer : 0;
482 else
483 return 0;
484 }
htb_hiwater(const struct htb_class * cl)485 static inline s64 htb_hiwater(const struct htb_class *cl)
486 {
487 if (htb_hysteresis)
488 return cl->cmode == HTB_CAN_SEND ? -cl->buffer : 0;
489 else
490 return 0;
491 }
492
493
494 /**
495 * htb_class_mode - computes and returns current class mode
496 *
497 * It computes cl's mode at time cl->t_c+diff and returns it. If mode
498 * is not HTB_CAN_SEND then cl->pq_key is updated to time difference
499 * from now to time when cl will change its state.
500 * Also it is worth to note that class mode doesn't change simply
501 * at cl->{c,}tokens == 0 but there can rather be hysteresis of
502 * 0 .. -cl->{c,}buffer range. It is meant to limit number of
503 * mode transitions per time unit. The speed gain is about 1/6.
504 */
505 static inline enum htb_cmode
htb_class_mode(struct htb_class * cl,s64 * diff)506 htb_class_mode(struct htb_class *cl, s64 *diff)
507 {
508 s64 toks;
509
510 if ((toks = (cl->ctokens + *diff)) < htb_lowater(cl)) {
511 *diff = -toks;
512 return HTB_CANT_SEND;
513 }
514
515 if ((toks = (cl->tokens + *diff)) >= htb_hiwater(cl))
516 return HTB_CAN_SEND;
517
518 *diff = -toks;
519 return HTB_MAY_BORROW;
520 }
521
522 /**
523 * htb_change_class_mode - changes classe's mode
524 *
525 * This should be the only way how to change classe's mode under normal
526 * cirsumstances. Routine will update feed lists linkage, change mode
527 * and add class to the wait event queue if appropriate. New mode should
528 * be different from old one and cl->pq_key has to be valid if changing
529 * to mode other than HTB_CAN_SEND (see htb_add_to_wait_tree).
530 */
531 static void
htb_change_class_mode(struct htb_sched * q,struct htb_class * cl,s64 * diff)532 htb_change_class_mode(struct htb_sched *q, struct htb_class *cl, s64 *diff)
533 {
534 enum htb_cmode new_mode = htb_class_mode(cl, diff);
535
536 if (new_mode == cl->cmode)
537 return;
538
539 if (new_mode == HTB_CANT_SEND) {
540 cl->overlimits++;
541 q->overlimits++;
542 }
543
544 if (cl->prio_activity) { /* not necessary: speed optimization */
545 if (cl->cmode != HTB_CANT_SEND)
546 htb_deactivate_prios(q, cl);
547 cl->cmode = new_mode;
548 if (new_mode != HTB_CANT_SEND)
549 htb_activate_prios(q, cl);
550 } else
551 cl->cmode = new_mode;
552 }
553
554 /**
555 * htb_activate - inserts leaf cl into appropriate active feeds
556 *
557 * Routine learns (new) priority of leaf and activates feed chain
558 * for the prio. It can be called on already active leaf safely.
559 * It also adds leaf into droplist.
560 */
htb_activate(struct htb_sched * q,struct htb_class * cl)561 static inline void htb_activate(struct htb_sched *q, struct htb_class *cl)
562 {
563 WARN_ON(cl->level || !cl->leaf.q || !cl->leaf.q->q.qlen);
564
565 if (!cl->prio_activity) {
566 cl->prio_activity = 1 << cl->prio;
567 htb_activate_prios(q, cl);
568 }
569 }
570
571 /**
572 * htb_deactivate - remove leaf cl from active feeds
573 *
574 * Make sure that leaf is active. In the other words it can't be called
575 * with non-active leaf. It also removes class from the drop list.
576 */
htb_deactivate(struct htb_sched * q,struct htb_class * cl)577 static inline void htb_deactivate(struct htb_sched *q, struct htb_class *cl)
578 {
579 WARN_ON(!cl->prio_activity);
580
581 htb_deactivate_prios(q, cl);
582 cl->prio_activity = 0;
583 }
584
htb_enqueue(struct sk_buff * skb,struct Qdisc * sch,struct sk_buff ** to_free)585 static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch,
586 struct sk_buff **to_free)
587 {
588 int ret;
589 unsigned int len = qdisc_pkt_len(skb);
590 struct htb_sched *q = qdisc_priv(sch);
591 struct htb_class *cl = htb_classify(skb, sch, &ret);
592
593 if (cl == HTB_DIRECT) {
594 /* enqueue to helper queue */
595 if (q->direct_queue.qlen < q->direct_qlen) {
596 __qdisc_enqueue_tail(skb, &q->direct_queue);
597 q->direct_pkts++;
598 } else {
599 return qdisc_drop(skb, sch, to_free);
600 }
601 #ifdef CONFIG_NET_CLS_ACT
602 } else if (!cl) {
603 if (ret & __NET_XMIT_BYPASS)
604 qdisc_qstats_drop(sch);
605 __qdisc_drop(skb, to_free);
606 return ret;
607 #endif
608 } else if ((ret = qdisc_enqueue(skb, cl->leaf.q,
609 to_free)) != NET_XMIT_SUCCESS) {
610 if (net_xmit_drop_count(ret)) {
611 qdisc_qstats_drop(sch);
612 cl->drops++;
613 }
614 return ret;
615 } else {
616 htb_activate(q, cl);
617 }
618
619 sch->qstats.backlog += len;
620 sch->q.qlen++;
621 return NET_XMIT_SUCCESS;
622 }
623
htb_accnt_tokens(struct htb_class * cl,int bytes,s64 diff)624 static inline void htb_accnt_tokens(struct htb_class *cl, int bytes, s64 diff)
625 {
626 s64 toks = diff + cl->tokens;
627
628 if (toks > cl->buffer)
629 toks = cl->buffer;
630 toks -= (s64) psched_l2t_ns(&cl->rate, bytes);
631 if (toks <= -cl->mbuffer)
632 toks = 1 - cl->mbuffer;
633
634 cl->tokens = toks;
635 }
636
htb_accnt_ctokens(struct htb_class * cl,int bytes,s64 diff)637 static inline void htb_accnt_ctokens(struct htb_class *cl, int bytes, s64 diff)
638 {
639 s64 toks = diff + cl->ctokens;
640
641 if (toks > cl->cbuffer)
642 toks = cl->cbuffer;
643 toks -= (s64) psched_l2t_ns(&cl->ceil, bytes);
644 if (toks <= -cl->mbuffer)
645 toks = 1 - cl->mbuffer;
646
647 cl->ctokens = toks;
648 }
649
650 /**
651 * htb_charge_class - charges amount "bytes" to leaf and ancestors
652 *
653 * Routine assumes that packet "bytes" long was dequeued from leaf cl
654 * borrowing from "level". It accounts bytes to ceil leaky bucket for
655 * leaf and all ancestors and to rate bucket for ancestors at levels
656 * "level" and higher. It also handles possible change of mode resulting
657 * from the update. Note that mode can also increase here (MAY_BORROW to
658 * CAN_SEND) because we can use more precise clock that event queue here.
659 * In such case we remove class from event queue first.
660 */
htb_charge_class(struct htb_sched * q,struct htb_class * cl,int level,struct sk_buff * skb)661 static void htb_charge_class(struct htb_sched *q, struct htb_class *cl,
662 int level, struct sk_buff *skb)
663 {
664 int bytes = qdisc_pkt_len(skb);
665 enum htb_cmode old_mode;
666 s64 diff;
667
668 while (cl) {
669 diff = min_t(s64, q->now - cl->t_c, cl->mbuffer);
670 if (cl->level >= level) {
671 if (cl->level == level)
672 cl->xstats.lends++;
673 htb_accnt_tokens(cl, bytes, diff);
674 } else {
675 cl->xstats.borrows++;
676 cl->tokens += diff; /* we moved t_c; update tokens */
677 }
678 htb_accnt_ctokens(cl, bytes, diff);
679 cl->t_c = q->now;
680
681 old_mode = cl->cmode;
682 diff = 0;
683 htb_change_class_mode(q, cl, &diff);
684 if (old_mode != cl->cmode) {
685 if (old_mode != HTB_CAN_SEND)
686 htb_safe_rb_erase(&cl->pq_node, &q->hlevel[cl->level].wait_pq);
687 if (cl->cmode != HTB_CAN_SEND)
688 htb_add_to_wait_tree(q, cl, diff);
689 }
690
691 /* update basic stats except for leaves which are already updated */
692 if (cl->level)
693 bstats_update(&cl->bstats, skb);
694
695 cl = cl->parent;
696 }
697 }
698
699 /**
700 * htb_do_events - make mode changes to classes at the level
701 *
702 * Scans event queue for pending events and applies them. Returns time of
703 * next pending event (0 for no event in pq, q->now for too many events).
704 * Note: Applied are events whose have cl->pq_key <= q->now.
705 */
htb_do_events(struct htb_sched * q,const int level,unsigned long start)706 static s64 htb_do_events(struct htb_sched *q, const int level,
707 unsigned long start)
708 {
709 /* don't run for longer than 2 jiffies; 2 is used instead of
710 * 1 to simplify things when jiffy is going to be incremented
711 * too soon
712 */
713 unsigned long stop_at = start + 2;
714 struct rb_root *wait_pq = &q->hlevel[level].wait_pq;
715
716 while (time_before(jiffies, stop_at)) {
717 struct htb_class *cl;
718 s64 diff;
719 struct rb_node *p = rb_first(wait_pq);
720
721 if (!p)
722 return 0;
723
724 cl = rb_entry(p, struct htb_class, pq_node);
725 if (cl->pq_key > q->now)
726 return cl->pq_key;
727
728 htb_safe_rb_erase(p, wait_pq);
729 diff = min_t(s64, q->now - cl->t_c, cl->mbuffer);
730 htb_change_class_mode(q, cl, &diff);
731 if (cl->cmode != HTB_CAN_SEND)
732 htb_add_to_wait_tree(q, cl, diff);
733 }
734
735 /* too much load - let's continue after a break for scheduling */
736 if (!(q->warned & HTB_WARN_TOOMANYEVENTS)) {
737 pr_warn("htb: too many events!\n");
738 q->warned |= HTB_WARN_TOOMANYEVENTS;
739 }
740
741 return q->now;
742 }
743
744 /* Returns class->node+prio from id-tree where classe's id is >= id. NULL
745 * is no such one exists.
746 */
htb_id_find_next_upper(int prio,struct rb_node * n,u32 id)747 static struct rb_node *htb_id_find_next_upper(int prio, struct rb_node *n,
748 u32 id)
749 {
750 struct rb_node *r = NULL;
751 while (n) {
752 struct htb_class *cl =
753 rb_entry(n, struct htb_class, node[prio]);
754
755 if (id > cl->common.classid) {
756 n = n->rb_right;
757 } else if (id < cl->common.classid) {
758 r = n;
759 n = n->rb_left;
760 } else {
761 return n;
762 }
763 }
764 return r;
765 }
766
767 /**
768 * htb_lookup_leaf - returns next leaf class in DRR order
769 *
770 * Find leaf where current feed pointers points to.
771 */
htb_lookup_leaf(struct htb_prio * hprio,const int prio)772 static struct htb_class *htb_lookup_leaf(struct htb_prio *hprio, const int prio)
773 {
774 int i;
775 struct {
776 struct rb_node *root;
777 struct rb_node **pptr;
778 u32 *pid;
779 } stk[TC_HTB_MAXDEPTH], *sp = stk;
780
781 BUG_ON(!hprio->row.rb_node);
782 sp->root = hprio->row.rb_node;
783 sp->pptr = &hprio->ptr;
784 sp->pid = &hprio->last_ptr_id;
785
786 for (i = 0; i < 65535; i++) {
787 if (!*sp->pptr && *sp->pid) {
788 /* ptr was invalidated but id is valid - try to recover
789 * the original or next ptr
790 */
791 *sp->pptr =
792 htb_id_find_next_upper(prio, sp->root, *sp->pid);
793 }
794 *sp->pid = 0; /* ptr is valid now so that remove this hint as it
795 * can become out of date quickly
796 */
797 if (!*sp->pptr) { /* we are at right end; rewind & go up */
798 *sp->pptr = sp->root;
799 while ((*sp->pptr)->rb_left)
800 *sp->pptr = (*sp->pptr)->rb_left;
801 if (sp > stk) {
802 sp--;
803 if (!*sp->pptr) {
804 WARN_ON(1);
805 return NULL;
806 }
807 htb_next_rb_node(sp->pptr);
808 }
809 } else {
810 struct htb_class *cl;
811 struct htb_prio *clp;
812
813 cl = rb_entry(*sp->pptr, struct htb_class, node[prio]);
814 if (!cl->level)
815 return cl;
816 clp = &cl->inner.clprio[prio];
817 (++sp)->root = clp->feed.rb_node;
818 sp->pptr = &clp->ptr;
819 sp->pid = &clp->last_ptr_id;
820 }
821 }
822 WARN_ON(1);
823 return NULL;
824 }
825
826 /* dequeues packet at given priority and level; call only if
827 * you are sure that there is active class at prio/level
828 */
htb_dequeue_tree(struct htb_sched * q,const int prio,const int level)829 static struct sk_buff *htb_dequeue_tree(struct htb_sched *q, const int prio,
830 const int level)
831 {
832 struct sk_buff *skb = NULL;
833 struct htb_class *cl, *start;
834 struct htb_level *hlevel = &q->hlevel[level];
835 struct htb_prio *hprio = &hlevel->hprio[prio];
836
837 /* look initial class up in the row */
838 start = cl = htb_lookup_leaf(hprio, prio);
839
840 do {
841 next:
842 if (unlikely(!cl))
843 return NULL;
844
845 /* class can be empty - it is unlikely but can be true if leaf
846 * qdisc drops packets in enqueue routine or if someone used
847 * graft operation on the leaf since last dequeue;
848 * simply deactivate and skip such class
849 */
850 if (unlikely(cl->leaf.q->q.qlen == 0)) {
851 struct htb_class *next;
852 htb_deactivate(q, cl);
853
854 /* row/level might become empty */
855 if ((q->row_mask[level] & (1 << prio)) == 0)
856 return NULL;
857
858 next = htb_lookup_leaf(hprio, prio);
859
860 if (cl == start) /* fix start if we just deleted it */
861 start = next;
862 cl = next;
863 goto next;
864 }
865
866 skb = cl->leaf.q->dequeue(cl->leaf.q);
867 if (likely(skb != NULL))
868 break;
869
870 qdisc_warn_nonwc("htb", cl->leaf.q);
871 htb_next_rb_node(level ? &cl->parent->inner.clprio[prio].ptr:
872 &q->hlevel[0].hprio[prio].ptr);
873 cl = htb_lookup_leaf(hprio, prio);
874
875 } while (cl != start);
876
877 if (likely(skb != NULL)) {
878 bstats_update(&cl->bstats, skb);
879 cl->leaf.deficit[level] -= qdisc_pkt_len(skb);
880 if (cl->leaf.deficit[level] < 0) {
881 cl->leaf.deficit[level] += cl->quantum;
882 htb_next_rb_node(level ? &cl->parent->inner.clprio[prio].ptr :
883 &q->hlevel[0].hprio[prio].ptr);
884 }
885 /* this used to be after charge_class but this constelation
886 * gives us slightly better performance
887 */
888 if (!cl->leaf.q->q.qlen)
889 htb_deactivate(q, cl);
890 htb_charge_class(q, cl, level, skb);
891 }
892 return skb;
893 }
894
htb_dequeue(struct Qdisc * sch)895 static struct sk_buff *htb_dequeue(struct Qdisc *sch)
896 {
897 struct sk_buff *skb;
898 struct htb_sched *q = qdisc_priv(sch);
899 int level;
900 s64 next_event;
901 unsigned long start_at;
902
903 /* try to dequeue direct packets as high prio (!) to minimize cpu work */
904 skb = __qdisc_dequeue_head(&q->direct_queue);
905 if (skb != NULL) {
906 ok:
907 qdisc_bstats_update(sch, skb);
908 qdisc_qstats_backlog_dec(sch, skb);
909 sch->q.qlen--;
910 return skb;
911 }
912
913 if (!sch->q.qlen)
914 goto fin;
915 q->now = ktime_get_ns();
916 start_at = jiffies;
917
918 next_event = q->now + 5LLU * NSEC_PER_SEC;
919
920 for (level = 0; level < TC_HTB_MAXDEPTH; level++) {
921 /* common case optimization - skip event handler quickly */
922 int m;
923 s64 event = q->near_ev_cache[level];
924
925 if (q->now >= event) {
926 event = htb_do_events(q, level, start_at);
927 if (!event)
928 event = q->now + NSEC_PER_SEC;
929 q->near_ev_cache[level] = event;
930 }
931
932 if (next_event > event)
933 next_event = event;
934
935 m = ~q->row_mask[level];
936 while (m != (int)(-1)) {
937 int prio = ffz(m);
938
939 m |= 1 << prio;
940 skb = htb_dequeue_tree(q, prio, level);
941 if (likely(skb != NULL))
942 goto ok;
943 }
944 }
945 if (likely(next_event > q->now))
946 qdisc_watchdog_schedule_ns(&q->watchdog, next_event);
947 else
948 schedule_work(&q->work);
949 fin:
950 return skb;
951 }
952
953 /* reset all classes */
954 /* always caled under BH & queue lock */
htb_reset(struct Qdisc * sch)955 static void htb_reset(struct Qdisc *sch)
956 {
957 struct htb_sched *q = qdisc_priv(sch);
958 struct htb_class *cl;
959 unsigned int i;
960
961 for (i = 0; i < q->clhash.hashsize; i++) {
962 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
963 if (cl->level)
964 memset(&cl->inner, 0, sizeof(cl->inner));
965 else {
966 if (cl->leaf.q && !q->offload)
967 qdisc_reset(cl->leaf.q);
968 }
969 cl->prio_activity = 0;
970 cl->cmode = HTB_CAN_SEND;
971 }
972 }
973 qdisc_watchdog_cancel(&q->watchdog);
974 __qdisc_reset_queue(&q->direct_queue);
975 sch->q.qlen = 0;
976 sch->qstats.backlog = 0;
977 memset(q->hlevel, 0, sizeof(q->hlevel));
978 memset(q->row_mask, 0, sizeof(q->row_mask));
979 }
980
981 static const struct nla_policy htb_policy[TCA_HTB_MAX + 1] = {
982 [TCA_HTB_PARMS] = { .len = sizeof(struct tc_htb_opt) },
983 [TCA_HTB_INIT] = { .len = sizeof(struct tc_htb_glob) },
984 [TCA_HTB_CTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
985 [TCA_HTB_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
986 [TCA_HTB_DIRECT_QLEN] = { .type = NLA_U32 },
987 [TCA_HTB_RATE64] = { .type = NLA_U64 },
988 [TCA_HTB_CEIL64] = { .type = NLA_U64 },
989 [TCA_HTB_OFFLOAD] = { .type = NLA_FLAG },
990 };
991
htb_work_func(struct work_struct * work)992 static void htb_work_func(struct work_struct *work)
993 {
994 struct htb_sched *q = container_of(work, struct htb_sched, work);
995 struct Qdisc *sch = q->watchdog.qdisc;
996
997 rcu_read_lock();
998 __netif_schedule(qdisc_root(sch));
999 rcu_read_unlock();
1000 }
1001
htb_set_lockdep_class_child(struct Qdisc * q)1002 static void htb_set_lockdep_class_child(struct Qdisc *q)
1003 {
1004 static struct lock_class_key child_key;
1005
1006 lockdep_set_class(qdisc_lock(q), &child_key);
1007 }
1008
htb_offload(struct net_device * dev,struct tc_htb_qopt_offload * opt)1009 static int htb_offload(struct net_device *dev, struct tc_htb_qopt_offload *opt)
1010 {
1011 return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_HTB, opt);
1012 }
1013
htb_init(struct Qdisc * sch,struct nlattr * opt,struct netlink_ext_ack * extack)1014 static int htb_init(struct Qdisc *sch, struct nlattr *opt,
1015 struct netlink_ext_ack *extack)
1016 {
1017 struct net_device *dev = qdisc_dev(sch);
1018 struct tc_htb_qopt_offload offload_opt;
1019 struct htb_sched *q = qdisc_priv(sch);
1020 struct nlattr *tb[TCA_HTB_MAX + 1];
1021 struct tc_htb_glob *gopt;
1022 unsigned int ntx;
1023 bool offload;
1024 int err;
1025
1026 qdisc_watchdog_init(&q->watchdog, sch);
1027 INIT_WORK(&q->work, htb_work_func);
1028
1029 if (!opt)
1030 return -EINVAL;
1031
1032 err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
1033 if (err)
1034 return err;
1035
1036 err = nla_parse_nested_deprecated(tb, TCA_HTB_MAX, opt, htb_policy,
1037 NULL);
1038 if (err < 0)
1039 return err;
1040
1041 if (!tb[TCA_HTB_INIT])
1042 return -EINVAL;
1043
1044 gopt = nla_data(tb[TCA_HTB_INIT]);
1045 if (gopt->version != HTB_VER >> 16)
1046 return -EINVAL;
1047
1048 offload = nla_get_flag(tb[TCA_HTB_OFFLOAD]);
1049
1050 if (offload) {
1051 if (sch->parent != TC_H_ROOT)
1052 return -EOPNOTSUPP;
1053
1054 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
1055 return -EOPNOTSUPP;
1056
1057 q->num_direct_qdiscs = dev->real_num_tx_queues;
1058 q->direct_qdiscs = kcalloc(q->num_direct_qdiscs,
1059 sizeof(*q->direct_qdiscs),
1060 GFP_KERNEL);
1061 if (!q->direct_qdiscs)
1062 return -ENOMEM;
1063 }
1064
1065 err = qdisc_class_hash_init(&q->clhash);
1066 if (err < 0)
1067 goto err_free_direct_qdiscs;
1068
1069 qdisc_skb_head_init(&q->direct_queue);
1070
1071 if (tb[TCA_HTB_DIRECT_QLEN])
1072 q->direct_qlen = nla_get_u32(tb[TCA_HTB_DIRECT_QLEN]);
1073 else
1074 q->direct_qlen = qdisc_dev(sch)->tx_queue_len;
1075
1076 if ((q->rate2quantum = gopt->rate2quantum) < 1)
1077 q->rate2quantum = 1;
1078 q->defcls = gopt->defcls;
1079
1080 if (!offload)
1081 return 0;
1082
1083 for (ntx = 0; ntx < q->num_direct_qdiscs; ntx++) {
1084 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, ntx);
1085 struct Qdisc *qdisc;
1086
1087 qdisc = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops,
1088 TC_H_MAKE(sch->handle, 0), extack);
1089 if (!qdisc) {
1090 err = -ENOMEM;
1091 goto err_free_qdiscs;
1092 }
1093
1094 htb_set_lockdep_class_child(qdisc);
1095 q->direct_qdiscs[ntx] = qdisc;
1096 qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
1097 }
1098
1099 sch->flags |= TCQ_F_MQROOT;
1100
1101 offload_opt = (struct tc_htb_qopt_offload) {
1102 .command = TC_HTB_CREATE,
1103 .parent_classid = TC_H_MAJ(sch->handle) >> 16,
1104 .classid = TC_H_MIN(q->defcls),
1105 .extack = extack,
1106 };
1107 err = htb_offload(dev, &offload_opt);
1108 if (err)
1109 goto err_free_qdiscs;
1110
1111 /* Defer this assignment, so that htb_destroy skips offload-related
1112 * parts (especially calling ndo_setup_tc) on errors.
1113 */
1114 q->offload = true;
1115
1116 return 0;
1117
1118 err_free_qdiscs:
1119 for (ntx = 0; ntx < q->num_direct_qdiscs && q->direct_qdiscs[ntx];
1120 ntx++)
1121 qdisc_put(q->direct_qdiscs[ntx]);
1122
1123 qdisc_class_hash_destroy(&q->clhash);
1124 /* Prevent use-after-free and double-free when htb_destroy gets called.
1125 */
1126 q->clhash.hash = NULL;
1127 q->clhash.hashsize = 0;
1128
1129 err_free_direct_qdiscs:
1130 kfree(q->direct_qdiscs);
1131 q->direct_qdiscs = NULL;
1132 return err;
1133 }
1134
htb_attach_offload(struct Qdisc * sch)1135 static void htb_attach_offload(struct Qdisc *sch)
1136 {
1137 struct net_device *dev = qdisc_dev(sch);
1138 struct htb_sched *q = qdisc_priv(sch);
1139 unsigned int ntx;
1140
1141 for (ntx = 0; ntx < q->num_direct_qdiscs; ntx++) {
1142 struct Qdisc *old, *qdisc = q->direct_qdiscs[ntx];
1143
1144 old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
1145 qdisc_put(old);
1146 qdisc_hash_add(qdisc, false);
1147 }
1148 for (ntx = q->num_direct_qdiscs; ntx < dev->num_tx_queues; ntx++) {
1149 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, ntx);
1150 struct Qdisc *old = dev_graft_qdisc(dev_queue, NULL);
1151
1152 qdisc_put(old);
1153 }
1154
1155 kfree(q->direct_qdiscs);
1156 q->direct_qdiscs = NULL;
1157 }
1158
htb_attach_software(struct Qdisc * sch)1159 static void htb_attach_software(struct Qdisc *sch)
1160 {
1161 struct net_device *dev = qdisc_dev(sch);
1162 unsigned int ntx;
1163
1164 /* Resemble qdisc_graft behavior. */
1165 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
1166 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, ntx);
1167 struct Qdisc *old = dev_graft_qdisc(dev_queue, sch);
1168
1169 qdisc_refcount_inc(sch);
1170
1171 qdisc_put(old);
1172 }
1173 }
1174
htb_attach(struct Qdisc * sch)1175 static void htb_attach(struct Qdisc *sch)
1176 {
1177 struct htb_sched *q = qdisc_priv(sch);
1178
1179 if (q->offload)
1180 htb_attach_offload(sch);
1181 else
1182 htb_attach_software(sch);
1183 }
1184
htb_dump(struct Qdisc * sch,struct sk_buff * skb)1185 static int htb_dump(struct Qdisc *sch, struct sk_buff *skb)
1186 {
1187 struct htb_sched *q = qdisc_priv(sch);
1188 struct nlattr *nest;
1189 struct tc_htb_glob gopt;
1190
1191 if (q->offload)
1192 sch->flags |= TCQ_F_OFFLOADED;
1193 else
1194 sch->flags &= ~TCQ_F_OFFLOADED;
1195
1196 sch->qstats.overlimits = q->overlimits;
1197 /* Its safe to not acquire qdisc lock. As we hold RTNL,
1198 * no change can happen on the qdisc parameters.
1199 */
1200
1201 gopt.direct_pkts = q->direct_pkts;
1202 gopt.version = HTB_VER;
1203 gopt.rate2quantum = q->rate2quantum;
1204 gopt.defcls = q->defcls;
1205 gopt.debug = 0;
1206
1207 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1208 if (nest == NULL)
1209 goto nla_put_failure;
1210 if (nla_put(skb, TCA_HTB_INIT, sizeof(gopt), &gopt) ||
1211 nla_put_u32(skb, TCA_HTB_DIRECT_QLEN, q->direct_qlen))
1212 goto nla_put_failure;
1213 if (q->offload && nla_put_flag(skb, TCA_HTB_OFFLOAD))
1214 goto nla_put_failure;
1215
1216 return nla_nest_end(skb, nest);
1217
1218 nla_put_failure:
1219 nla_nest_cancel(skb, nest);
1220 return -1;
1221 }
1222
htb_dump_class(struct Qdisc * sch,unsigned long arg,struct sk_buff * skb,struct tcmsg * tcm)1223 static int htb_dump_class(struct Qdisc *sch, unsigned long arg,
1224 struct sk_buff *skb, struct tcmsg *tcm)
1225 {
1226 struct htb_class *cl = (struct htb_class *)arg;
1227 struct htb_sched *q = qdisc_priv(sch);
1228 struct nlattr *nest;
1229 struct tc_htb_opt opt;
1230
1231 /* Its safe to not acquire qdisc lock. As we hold RTNL,
1232 * no change can happen on the class parameters.
1233 */
1234 tcm->tcm_parent = cl->parent ? cl->parent->common.classid : TC_H_ROOT;
1235 tcm->tcm_handle = cl->common.classid;
1236 if (!cl->level && cl->leaf.q)
1237 tcm->tcm_info = cl->leaf.q->handle;
1238
1239 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1240 if (nest == NULL)
1241 goto nla_put_failure;
1242
1243 memset(&opt, 0, sizeof(opt));
1244
1245 psched_ratecfg_getrate(&opt.rate, &cl->rate);
1246 opt.buffer = PSCHED_NS2TICKS(cl->buffer);
1247 psched_ratecfg_getrate(&opt.ceil, &cl->ceil);
1248 opt.cbuffer = PSCHED_NS2TICKS(cl->cbuffer);
1249 opt.quantum = cl->quantum;
1250 opt.prio = cl->prio;
1251 opt.level = cl->level;
1252 if (nla_put(skb, TCA_HTB_PARMS, sizeof(opt), &opt))
1253 goto nla_put_failure;
1254 if (q->offload && nla_put_flag(skb, TCA_HTB_OFFLOAD))
1255 goto nla_put_failure;
1256 if ((cl->rate.rate_bytes_ps >= (1ULL << 32)) &&
1257 nla_put_u64_64bit(skb, TCA_HTB_RATE64, cl->rate.rate_bytes_ps,
1258 TCA_HTB_PAD))
1259 goto nla_put_failure;
1260 if ((cl->ceil.rate_bytes_ps >= (1ULL << 32)) &&
1261 nla_put_u64_64bit(skb, TCA_HTB_CEIL64, cl->ceil.rate_bytes_ps,
1262 TCA_HTB_PAD))
1263 goto nla_put_failure;
1264
1265 return nla_nest_end(skb, nest);
1266
1267 nla_put_failure:
1268 nla_nest_cancel(skb, nest);
1269 return -1;
1270 }
1271
htb_offload_aggregate_stats(struct htb_sched * q,struct htb_class * cl)1272 static void htb_offload_aggregate_stats(struct htb_sched *q,
1273 struct htb_class *cl)
1274 {
1275 struct htb_class *c;
1276 unsigned int i;
1277
1278 memset(&cl->bstats, 0, sizeof(cl->bstats));
1279
1280 for (i = 0; i < q->clhash.hashsize; i++) {
1281 hlist_for_each_entry(c, &q->clhash.hash[i], common.hnode) {
1282 struct htb_class *p = c;
1283
1284 while (p && p->level < cl->level)
1285 p = p->parent;
1286
1287 if (p != cl)
1288 continue;
1289
1290 cl->bstats.bytes += c->bstats_bias.bytes;
1291 cl->bstats.packets += c->bstats_bias.packets;
1292 if (c->level == 0) {
1293 cl->bstats.bytes += c->leaf.q->bstats.bytes;
1294 cl->bstats.packets += c->leaf.q->bstats.packets;
1295 }
1296 }
1297 }
1298 }
1299
1300 static int
htb_dump_class_stats(struct Qdisc * sch,unsigned long arg,struct gnet_dump * d)1301 htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d)
1302 {
1303 struct htb_class *cl = (struct htb_class *)arg;
1304 struct htb_sched *q = qdisc_priv(sch);
1305 struct gnet_stats_queue qs = {
1306 .drops = cl->drops,
1307 .overlimits = cl->overlimits,
1308 };
1309 __u32 qlen = 0;
1310
1311 if (!cl->level && cl->leaf.q)
1312 qdisc_qstats_qlen_backlog(cl->leaf.q, &qlen, &qs.backlog);
1313
1314 cl->xstats.tokens = clamp_t(s64, PSCHED_NS2TICKS(cl->tokens),
1315 INT_MIN, INT_MAX);
1316 cl->xstats.ctokens = clamp_t(s64, PSCHED_NS2TICKS(cl->ctokens),
1317 INT_MIN, INT_MAX);
1318
1319 if (q->offload) {
1320 if (!cl->level) {
1321 if (cl->leaf.q)
1322 cl->bstats = cl->leaf.q->bstats;
1323 else
1324 memset(&cl->bstats, 0, sizeof(cl->bstats));
1325 cl->bstats.bytes += cl->bstats_bias.bytes;
1326 cl->bstats.packets += cl->bstats_bias.packets;
1327 } else {
1328 htb_offload_aggregate_stats(q, cl);
1329 }
1330 }
1331
1332 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
1333 d, NULL, &cl->bstats) < 0 ||
1334 gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
1335 gnet_stats_copy_queue(d, NULL, &qs, qlen) < 0)
1336 return -1;
1337
1338 return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));
1339 }
1340
1341 static struct netdev_queue *
htb_select_queue(struct Qdisc * sch,struct tcmsg * tcm)1342 htb_select_queue(struct Qdisc *sch, struct tcmsg *tcm)
1343 {
1344 struct net_device *dev = qdisc_dev(sch);
1345 struct tc_htb_qopt_offload offload_opt;
1346 struct htb_sched *q = qdisc_priv(sch);
1347 int err;
1348
1349 if (!q->offload)
1350 return sch->dev_queue;
1351
1352 offload_opt = (struct tc_htb_qopt_offload) {
1353 .command = TC_HTB_LEAF_QUERY_QUEUE,
1354 .classid = TC_H_MIN(tcm->tcm_parent),
1355 };
1356 err = htb_offload(dev, &offload_opt);
1357 if (err || offload_opt.qid >= dev->num_tx_queues)
1358 return NULL;
1359 return netdev_get_tx_queue(dev, offload_opt.qid);
1360 }
1361
1362 static struct Qdisc *
htb_graft_helper(struct netdev_queue * dev_queue,struct Qdisc * new_q)1363 htb_graft_helper(struct netdev_queue *dev_queue, struct Qdisc *new_q)
1364 {
1365 struct net_device *dev = dev_queue->dev;
1366 struct Qdisc *old_q;
1367
1368 if (dev->flags & IFF_UP)
1369 dev_deactivate(dev);
1370 old_q = dev_graft_qdisc(dev_queue, new_q);
1371 if (new_q)
1372 new_q->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
1373 if (dev->flags & IFF_UP)
1374 dev_activate(dev);
1375
1376 return old_q;
1377 }
1378
htb_offload_move_qdisc(struct Qdisc * sch,u16 qid_old,u16 qid_new)1379 static void htb_offload_move_qdisc(struct Qdisc *sch, u16 qid_old, u16 qid_new)
1380 {
1381 struct netdev_queue *queue_old, *queue_new;
1382 struct net_device *dev = qdisc_dev(sch);
1383 struct Qdisc *qdisc;
1384
1385 queue_old = netdev_get_tx_queue(dev, qid_old);
1386 queue_new = netdev_get_tx_queue(dev, qid_new);
1387
1388 if (dev->flags & IFF_UP)
1389 dev_deactivate(dev);
1390 qdisc = dev_graft_qdisc(queue_old, NULL);
1391 qdisc->dev_queue = queue_new;
1392 qdisc = dev_graft_qdisc(queue_new, qdisc);
1393 if (dev->flags & IFF_UP)
1394 dev_activate(dev);
1395
1396 WARN_ON(!(qdisc->flags & TCQ_F_BUILTIN));
1397 }
1398
htb_graft(struct Qdisc * sch,unsigned long arg,struct Qdisc * new,struct Qdisc ** old,struct netlink_ext_ack * extack)1399 static int htb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1400 struct Qdisc **old, struct netlink_ext_ack *extack)
1401 {
1402 struct netdev_queue *dev_queue = sch->dev_queue;
1403 struct htb_class *cl = (struct htb_class *)arg;
1404 struct htb_sched *q = qdisc_priv(sch);
1405 struct Qdisc *old_q;
1406
1407 if (cl->level)
1408 return -EINVAL;
1409
1410 if (q->offload) {
1411 dev_queue = new->dev_queue;
1412 WARN_ON(dev_queue != cl->leaf.q->dev_queue);
1413 }
1414
1415 if (!new) {
1416 new = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops,
1417 cl->common.classid, extack);
1418 if (!new)
1419 return -ENOBUFS;
1420 }
1421
1422 if (q->offload) {
1423 htb_set_lockdep_class_child(new);
1424 /* One ref for cl->leaf.q, the other for dev_queue->qdisc. */
1425 qdisc_refcount_inc(new);
1426 old_q = htb_graft_helper(dev_queue, new);
1427 }
1428
1429 *old = qdisc_replace(sch, new, &cl->leaf.q);
1430
1431 if (q->offload) {
1432 WARN_ON(old_q != *old);
1433 qdisc_put(old_q);
1434 }
1435
1436 return 0;
1437 }
1438
htb_leaf(struct Qdisc * sch,unsigned long arg)1439 static struct Qdisc *htb_leaf(struct Qdisc *sch, unsigned long arg)
1440 {
1441 struct htb_class *cl = (struct htb_class *)arg;
1442 return !cl->level ? cl->leaf.q : NULL;
1443 }
1444
htb_qlen_notify(struct Qdisc * sch,unsigned long arg)1445 static void htb_qlen_notify(struct Qdisc *sch, unsigned long arg)
1446 {
1447 struct htb_class *cl = (struct htb_class *)arg;
1448
1449 htb_deactivate(qdisc_priv(sch), cl);
1450 }
1451
htb_parent_last_child(struct htb_class * cl)1452 static inline int htb_parent_last_child(struct htb_class *cl)
1453 {
1454 if (!cl->parent)
1455 /* the root class */
1456 return 0;
1457 if (cl->parent->children > 1)
1458 /* not the last child */
1459 return 0;
1460 return 1;
1461 }
1462
htb_parent_to_leaf(struct Qdisc * sch,struct htb_class * cl,struct Qdisc * new_q)1463 static void htb_parent_to_leaf(struct Qdisc *sch, struct htb_class *cl,
1464 struct Qdisc *new_q)
1465 {
1466 struct htb_sched *q = qdisc_priv(sch);
1467 struct htb_class *parent = cl->parent;
1468
1469 WARN_ON(cl->level || !cl->leaf.q || cl->prio_activity);
1470
1471 if (parent->cmode != HTB_CAN_SEND)
1472 htb_safe_rb_erase(&parent->pq_node,
1473 &q->hlevel[parent->level].wait_pq);
1474
1475 parent->level = 0;
1476 memset(&parent->inner, 0, sizeof(parent->inner));
1477 parent->leaf.q = new_q ? new_q : &noop_qdisc;
1478 parent->tokens = parent->buffer;
1479 parent->ctokens = parent->cbuffer;
1480 parent->t_c = ktime_get_ns();
1481 parent->cmode = HTB_CAN_SEND;
1482 }
1483
htb_parent_to_leaf_offload(struct Qdisc * sch,struct netdev_queue * dev_queue,struct Qdisc * new_q)1484 static void htb_parent_to_leaf_offload(struct Qdisc *sch,
1485 struct netdev_queue *dev_queue,
1486 struct Qdisc *new_q)
1487 {
1488 struct Qdisc *old_q;
1489
1490 /* One ref for cl->leaf.q, the other for dev_queue->qdisc. */
1491 qdisc_refcount_inc(new_q);
1492 old_q = htb_graft_helper(dev_queue, new_q);
1493 WARN_ON(!(old_q->flags & TCQ_F_BUILTIN));
1494 }
1495
htb_destroy_class_offload(struct Qdisc * sch,struct htb_class * cl,bool last_child,bool destroying,struct netlink_ext_ack * extack)1496 static int htb_destroy_class_offload(struct Qdisc *sch, struct htb_class *cl,
1497 bool last_child, bool destroying,
1498 struct netlink_ext_ack *extack)
1499 {
1500 struct tc_htb_qopt_offload offload_opt;
1501 struct Qdisc *q = cl->leaf.q;
1502 struct Qdisc *old = NULL;
1503 int err;
1504
1505 if (cl->level)
1506 return -EINVAL;
1507
1508 WARN_ON(!q);
1509 if (!destroying) {
1510 /* On destroy of HTB, two cases are possible:
1511 * 1. q is a normal qdisc, but q->dev_queue has noop qdisc.
1512 * 2. q is a noop qdisc (for nodes that were inner),
1513 * q->dev_queue is noop_netdev_queue.
1514 */
1515 old = htb_graft_helper(q->dev_queue, NULL);
1516 WARN_ON(!old);
1517 WARN_ON(old != q);
1518 }
1519
1520 if (cl->parent) {
1521 cl->parent->bstats_bias.bytes += q->bstats.bytes;
1522 cl->parent->bstats_bias.packets += q->bstats.packets;
1523 }
1524
1525 offload_opt = (struct tc_htb_qopt_offload) {
1526 .command = !last_child ? TC_HTB_LEAF_DEL :
1527 destroying ? TC_HTB_LEAF_DEL_LAST_FORCE :
1528 TC_HTB_LEAF_DEL_LAST,
1529 .classid = cl->common.classid,
1530 .extack = extack,
1531 };
1532 err = htb_offload(qdisc_dev(sch), &offload_opt);
1533
1534 if (!err || destroying)
1535 qdisc_put(old);
1536 else
1537 htb_graft_helper(q->dev_queue, old);
1538
1539 if (last_child)
1540 return err;
1541
1542 if (!err && offload_opt.moved_qid != 0) {
1543 if (destroying)
1544 q->dev_queue = netdev_get_tx_queue(qdisc_dev(sch),
1545 offload_opt.qid);
1546 else
1547 htb_offload_move_qdisc(sch, offload_opt.moved_qid,
1548 offload_opt.qid);
1549 }
1550
1551 return err;
1552 }
1553
htb_destroy_class(struct Qdisc * sch,struct htb_class * cl)1554 static void htb_destroy_class(struct Qdisc *sch, struct htb_class *cl)
1555 {
1556 if (!cl->level) {
1557 WARN_ON(!cl->leaf.q);
1558 qdisc_put(cl->leaf.q);
1559 }
1560 gen_kill_estimator(&cl->rate_est);
1561 tcf_block_put(cl->block);
1562 kfree(cl);
1563 }
1564
htb_destroy(struct Qdisc * sch)1565 static void htb_destroy(struct Qdisc *sch)
1566 {
1567 struct net_device *dev = qdisc_dev(sch);
1568 struct tc_htb_qopt_offload offload_opt;
1569 struct htb_sched *q = qdisc_priv(sch);
1570 struct hlist_node *next;
1571 bool nonempty, changed;
1572 struct htb_class *cl;
1573 unsigned int i;
1574
1575 cancel_work_sync(&q->work);
1576 qdisc_watchdog_cancel(&q->watchdog);
1577 /* This line used to be after htb_destroy_class call below
1578 * and surprisingly it worked in 2.4. But it must precede it
1579 * because filter need its target class alive to be able to call
1580 * unbind_filter on it (without Oops).
1581 */
1582 tcf_block_put(q->block);
1583
1584 for (i = 0; i < q->clhash.hashsize; i++) {
1585 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
1586 tcf_block_put(cl->block);
1587 cl->block = NULL;
1588 }
1589 }
1590
1591 do {
1592 nonempty = false;
1593 changed = false;
1594 for (i = 0; i < q->clhash.hashsize; i++) {
1595 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
1596 common.hnode) {
1597 bool last_child;
1598
1599 if (!q->offload) {
1600 htb_destroy_class(sch, cl);
1601 continue;
1602 }
1603
1604 nonempty = true;
1605
1606 if (cl->level)
1607 continue;
1608
1609 changed = true;
1610
1611 last_child = htb_parent_last_child(cl);
1612 htb_destroy_class_offload(sch, cl, last_child,
1613 true, NULL);
1614 qdisc_class_hash_remove(&q->clhash,
1615 &cl->common);
1616 if (cl->parent)
1617 cl->parent->children--;
1618 if (last_child)
1619 htb_parent_to_leaf(sch, cl, NULL);
1620 htb_destroy_class(sch, cl);
1621 }
1622 }
1623 } while (changed);
1624 WARN_ON(nonempty);
1625
1626 qdisc_class_hash_destroy(&q->clhash);
1627 __qdisc_reset_queue(&q->direct_queue);
1628
1629 if (!q->offload)
1630 return;
1631
1632 offload_opt = (struct tc_htb_qopt_offload) {
1633 .command = TC_HTB_DESTROY,
1634 };
1635 htb_offload(dev, &offload_opt);
1636
1637 if (!q->direct_qdiscs)
1638 return;
1639 for (i = 0; i < q->num_direct_qdiscs && q->direct_qdiscs[i]; i++)
1640 qdisc_put(q->direct_qdiscs[i]);
1641 kfree(q->direct_qdiscs);
1642 }
1643
htb_delete(struct Qdisc * sch,unsigned long arg,struct netlink_ext_ack * extack)1644 static int htb_delete(struct Qdisc *sch, unsigned long arg,
1645 struct netlink_ext_ack *extack)
1646 {
1647 struct htb_sched *q = qdisc_priv(sch);
1648 struct htb_class *cl = (struct htb_class *)arg;
1649 struct Qdisc *new_q = NULL;
1650 int last_child = 0;
1651 int err;
1652
1653 /* TODO: why don't allow to delete subtree ? references ? does
1654 * tc subsys guarantee us that in htb_destroy it holds no class
1655 * refs so that we can remove children safely there ?
1656 */
1657 if (cl->children || cl->filter_cnt)
1658 return -EBUSY;
1659
1660 if (!cl->level && htb_parent_last_child(cl))
1661 last_child = 1;
1662
1663 if (q->offload) {
1664 err = htb_destroy_class_offload(sch, cl, last_child, false,
1665 extack);
1666 if (err)
1667 return err;
1668 }
1669
1670 if (last_child) {
1671 struct netdev_queue *dev_queue;
1672
1673 dev_queue = q->offload ? cl->leaf.q->dev_queue : sch->dev_queue;
1674 new_q = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops,
1675 cl->parent->common.classid,
1676 NULL);
1677 if (q->offload) {
1678 if (new_q) {
1679 htb_set_lockdep_class_child(new_q);
1680 htb_parent_to_leaf_offload(sch, dev_queue, new_q);
1681 }
1682 }
1683 }
1684
1685 sch_tree_lock(sch);
1686
1687 if (!cl->level)
1688 qdisc_purge_queue(cl->leaf.q);
1689
1690 /* delete from hash and active; remainder in destroy_class */
1691 qdisc_class_hash_remove(&q->clhash, &cl->common);
1692 if (cl->parent)
1693 cl->parent->children--;
1694
1695 if (cl->prio_activity)
1696 htb_deactivate(q, cl);
1697
1698 if (cl->cmode != HTB_CAN_SEND)
1699 htb_safe_rb_erase(&cl->pq_node,
1700 &q->hlevel[cl->level].wait_pq);
1701
1702 if (last_child)
1703 htb_parent_to_leaf(sch, cl, new_q);
1704
1705 sch_tree_unlock(sch);
1706
1707 htb_destroy_class(sch, cl);
1708 return 0;
1709 }
1710
htb_change_class(struct Qdisc * sch,u32 classid,u32 parentid,struct nlattr ** tca,unsigned long * arg,struct netlink_ext_ack * extack)1711 static int htb_change_class(struct Qdisc *sch, u32 classid,
1712 u32 parentid, struct nlattr **tca,
1713 unsigned long *arg, struct netlink_ext_ack *extack)
1714 {
1715 int err = -EINVAL;
1716 struct htb_sched *q = qdisc_priv(sch);
1717 struct htb_class *cl = (struct htb_class *)*arg, *parent;
1718 struct tc_htb_qopt_offload offload_opt;
1719 struct nlattr *opt = tca[TCA_OPTIONS];
1720 struct nlattr *tb[TCA_HTB_MAX + 1];
1721 struct Qdisc *parent_qdisc = NULL;
1722 struct netdev_queue *dev_queue;
1723 struct tc_htb_opt *hopt;
1724 u64 rate64, ceil64;
1725 int warn = 0;
1726
1727 /* extract all subattrs from opt attr */
1728 if (!opt)
1729 goto failure;
1730
1731 err = nla_parse_nested_deprecated(tb, TCA_HTB_MAX, opt, htb_policy,
1732 NULL);
1733 if (err < 0)
1734 goto failure;
1735
1736 err = -EINVAL;
1737 if (tb[TCA_HTB_PARMS] == NULL)
1738 goto failure;
1739
1740 parent = parentid == TC_H_ROOT ? NULL : htb_find(parentid, sch);
1741
1742 hopt = nla_data(tb[TCA_HTB_PARMS]);
1743 if (!hopt->rate.rate || !hopt->ceil.rate)
1744 goto failure;
1745
1746 /* Keeping backward compatible with rate_table based iproute2 tc */
1747 if (hopt->rate.linklayer == TC_LINKLAYER_UNAWARE)
1748 qdisc_put_rtab(qdisc_get_rtab(&hopt->rate, tb[TCA_HTB_RTAB],
1749 NULL));
1750
1751 if (hopt->ceil.linklayer == TC_LINKLAYER_UNAWARE)
1752 qdisc_put_rtab(qdisc_get_rtab(&hopt->ceil, tb[TCA_HTB_CTAB],
1753 NULL));
1754
1755 rate64 = tb[TCA_HTB_RATE64] ? nla_get_u64(tb[TCA_HTB_RATE64]) : 0;
1756 ceil64 = tb[TCA_HTB_CEIL64] ? nla_get_u64(tb[TCA_HTB_CEIL64]) : 0;
1757
1758 if (!cl) { /* new class */
1759 struct net_device *dev = qdisc_dev(sch);
1760 struct Qdisc *new_q, *old_q;
1761 int prio;
1762 struct {
1763 struct nlattr nla;
1764 struct gnet_estimator opt;
1765 } est = {
1766 .nla = {
1767 .nla_len = nla_attr_size(sizeof(est.opt)),
1768 .nla_type = TCA_RATE,
1769 },
1770 .opt = {
1771 /* 4s interval, 16s averaging constant */
1772 .interval = 2,
1773 .ewma_log = 2,
1774 },
1775 };
1776
1777 /* check for valid classid */
1778 if (!classid || TC_H_MAJ(classid ^ sch->handle) ||
1779 htb_find(classid, sch))
1780 goto failure;
1781
1782 /* check maximal depth */
1783 if (parent && parent->parent && parent->parent->level < 2) {
1784 pr_err("htb: tree is too deep\n");
1785 goto failure;
1786 }
1787 err = -ENOBUFS;
1788 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
1789 if (!cl)
1790 goto failure;
1791
1792 err = tcf_block_get(&cl->block, &cl->filter_list, sch, extack);
1793 if (err) {
1794 kfree(cl);
1795 goto failure;
1796 }
1797 if (htb_rate_est || tca[TCA_RATE]) {
1798 err = gen_new_estimator(&cl->bstats, NULL,
1799 &cl->rate_est,
1800 NULL,
1801 qdisc_root_sleeping_running(sch),
1802 tca[TCA_RATE] ? : &est.nla);
1803 if (err)
1804 goto err_block_put;
1805 }
1806
1807 cl->children = 0;
1808 RB_CLEAR_NODE(&cl->pq_node);
1809
1810 for (prio = 0; prio < TC_HTB_NUMPRIO; prio++)
1811 RB_CLEAR_NODE(&cl->node[prio]);
1812
1813 cl->common.classid = classid;
1814
1815 /* Make sure nothing interrupts us in between of two
1816 * ndo_setup_tc calls.
1817 */
1818 ASSERT_RTNL();
1819
1820 /* create leaf qdisc early because it uses kmalloc(GFP_KERNEL)
1821 * so that can't be used inside of sch_tree_lock
1822 * -- thanks to Karlis Peisenieks
1823 */
1824 if (!q->offload) {
1825 dev_queue = sch->dev_queue;
1826 } else if (!(parent && !parent->level)) {
1827 /* Assign a dev_queue to this classid. */
1828 offload_opt = (struct tc_htb_qopt_offload) {
1829 .command = TC_HTB_LEAF_ALLOC_QUEUE,
1830 .classid = cl->common.classid,
1831 .parent_classid = parent ?
1832 TC_H_MIN(parent->common.classid) :
1833 TC_HTB_CLASSID_ROOT,
1834 .rate = max_t(u64, hopt->rate.rate, rate64),
1835 .ceil = max_t(u64, hopt->ceil.rate, ceil64),
1836 .extack = extack,
1837 };
1838 err = htb_offload(dev, &offload_opt);
1839 if (err) {
1840 pr_err("htb: TC_HTB_LEAF_ALLOC_QUEUE failed with err = %d\n",
1841 err);
1842 goto err_kill_estimator;
1843 }
1844 dev_queue = netdev_get_tx_queue(dev, offload_opt.qid);
1845 } else { /* First child. */
1846 dev_queue = parent->leaf.q->dev_queue;
1847 old_q = htb_graft_helper(dev_queue, NULL);
1848 WARN_ON(old_q != parent->leaf.q);
1849 offload_opt = (struct tc_htb_qopt_offload) {
1850 .command = TC_HTB_LEAF_TO_INNER,
1851 .classid = cl->common.classid,
1852 .parent_classid =
1853 TC_H_MIN(parent->common.classid),
1854 .rate = max_t(u64, hopt->rate.rate, rate64),
1855 .ceil = max_t(u64, hopt->ceil.rate, ceil64),
1856 .extack = extack,
1857 };
1858 err = htb_offload(dev, &offload_opt);
1859 if (err) {
1860 pr_err("htb: TC_HTB_LEAF_TO_INNER failed with err = %d\n",
1861 err);
1862 htb_graft_helper(dev_queue, old_q);
1863 goto err_kill_estimator;
1864 }
1865 parent->bstats_bias.bytes += old_q->bstats.bytes;
1866 parent->bstats_bias.packets += old_q->bstats.packets;
1867 qdisc_put(old_q);
1868 }
1869 new_q = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops,
1870 classid, NULL);
1871 if (q->offload) {
1872 if (new_q) {
1873 htb_set_lockdep_class_child(new_q);
1874 /* One ref for cl->leaf.q, the other for
1875 * dev_queue->qdisc.
1876 */
1877 qdisc_refcount_inc(new_q);
1878 }
1879 old_q = htb_graft_helper(dev_queue, new_q);
1880 /* No qdisc_put needed. */
1881 WARN_ON(!(old_q->flags & TCQ_F_BUILTIN));
1882 }
1883 sch_tree_lock(sch);
1884 if (parent && !parent->level) {
1885 /* turn parent into inner node */
1886 qdisc_purge_queue(parent->leaf.q);
1887 parent_qdisc = parent->leaf.q;
1888 if (parent->prio_activity)
1889 htb_deactivate(q, parent);
1890
1891 /* remove from evt list because of level change */
1892 if (parent->cmode != HTB_CAN_SEND) {
1893 htb_safe_rb_erase(&parent->pq_node, &q->hlevel[0].wait_pq);
1894 parent->cmode = HTB_CAN_SEND;
1895 }
1896 parent->level = (parent->parent ? parent->parent->level
1897 : TC_HTB_MAXDEPTH) - 1;
1898 memset(&parent->inner, 0, sizeof(parent->inner));
1899 }
1900
1901 /* leaf (we) needs elementary qdisc */
1902 cl->leaf.q = new_q ? new_q : &noop_qdisc;
1903
1904 cl->parent = parent;
1905
1906 /* set class to be in HTB_CAN_SEND state */
1907 cl->tokens = PSCHED_TICKS2NS(hopt->buffer);
1908 cl->ctokens = PSCHED_TICKS2NS(hopt->cbuffer);
1909 cl->mbuffer = 60ULL * NSEC_PER_SEC; /* 1min */
1910 cl->t_c = ktime_get_ns();
1911 cl->cmode = HTB_CAN_SEND;
1912
1913 /* attach to the hash list and parent's family */
1914 qdisc_class_hash_insert(&q->clhash, &cl->common);
1915 if (parent)
1916 parent->children++;
1917 if (cl->leaf.q != &noop_qdisc)
1918 qdisc_hash_add(cl->leaf.q, true);
1919 } else {
1920 if (tca[TCA_RATE]) {
1921 err = gen_replace_estimator(&cl->bstats, NULL,
1922 &cl->rate_est,
1923 NULL,
1924 qdisc_root_sleeping_running(sch),
1925 tca[TCA_RATE]);
1926 if (err)
1927 return err;
1928 }
1929
1930 if (q->offload) {
1931 struct net_device *dev = qdisc_dev(sch);
1932
1933 offload_opt = (struct tc_htb_qopt_offload) {
1934 .command = TC_HTB_NODE_MODIFY,
1935 .classid = cl->common.classid,
1936 .rate = max_t(u64, hopt->rate.rate, rate64),
1937 .ceil = max_t(u64, hopt->ceil.rate, ceil64),
1938 .extack = extack,
1939 };
1940 err = htb_offload(dev, &offload_opt);
1941 if (err)
1942 /* Estimator was replaced, and rollback may fail
1943 * as well, so we don't try to recover it, and
1944 * the estimator won't work property with the
1945 * offload anyway, because bstats are updated
1946 * only when the stats are queried.
1947 */
1948 return err;
1949 }
1950
1951 sch_tree_lock(sch);
1952 }
1953
1954 psched_ratecfg_precompute(&cl->rate, &hopt->rate, rate64);
1955 psched_ratecfg_precompute(&cl->ceil, &hopt->ceil, ceil64);
1956
1957 /* it used to be a nasty bug here, we have to check that node
1958 * is really leaf before changing cl->leaf !
1959 */
1960 if (!cl->level) {
1961 u64 quantum = cl->rate.rate_bytes_ps;
1962
1963 do_div(quantum, q->rate2quantum);
1964 cl->quantum = min_t(u64, quantum, INT_MAX);
1965
1966 if (!hopt->quantum && cl->quantum < 1000) {
1967 warn = -1;
1968 cl->quantum = 1000;
1969 }
1970 if (!hopt->quantum && cl->quantum > 200000) {
1971 warn = 1;
1972 cl->quantum = 200000;
1973 }
1974 if (hopt->quantum)
1975 cl->quantum = hopt->quantum;
1976 if ((cl->prio = hopt->prio) >= TC_HTB_NUMPRIO)
1977 cl->prio = TC_HTB_NUMPRIO - 1;
1978 }
1979
1980 cl->buffer = PSCHED_TICKS2NS(hopt->buffer);
1981 cl->cbuffer = PSCHED_TICKS2NS(hopt->cbuffer);
1982
1983 sch_tree_unlock(sch);
1984 qdisc_put(parent_qdisc);
1985
1986 if (warn)
1987 pr_warn("HTB: quantum of class %X is %s. Consider r2q change.\n",
1988 cl->common.classid, (warn == -1 ? "small" : "big"));
1989
1990 qdisc_class_hash_grow(sch, &q->clhash);
1991
1992 *arg = (unsigned long)cl;
1993 return 0;
1994
1995 err_kill_estimator:
1996 gen_kill_estimator(&cl->rate_est);
1997 err_block_put:
1998 tcf_block_put(cl->block);
1999 kfree(cl);
2000 failure:
2001 return err;
2002 }
2003
htb_tcf_block(struct Qdisc * sch,unsigned long arg,struct netlink_ext_ack * extack)2004 static struct tcf_block *htb_tcf_block(struct Qdisc *sch, unsigned long arg,
2005 struct netlink_ext_ack *extack)
2006 {
2007 struct htb_sched *q = qdisc_priv(sch);
2008 struct htb_class *cl = (struct htb_class *)arg;
2009
2010 return cl ? cl->block : q->block;
2011 }
2012
htb_bind_filter(struct Qdisc * sch,unsigned long parent,u32 classid)2013 static unsigned long htb_bind_filter(struct Qdisc *sch, unsigned long parent,
2014 u32 classid)
2015 {
2016 struct htb_class *cl = htb_find(classid, sch);
2017
2018 /*if (cl && !cl->level) return 0;
2019 * The line above used to be there to prevent attaching filters to
2020 * leaves. But at least tc_index filter uses this just to get class
2021 * for other reasons so that we have to allow for it.
2022 * ----
2023 * 19.6.2002 As Werner explained it is ok - bind filter is just
2024 * another way to "lock" the class - unlike "get" this lock can
2025 * be broken by class during destroy IIUC.
2026 */
2027 if (cl)
2028 cl->filter_cnt++;
2029 return (unsigned long)cl;
2030 }
2031
htb_unbind_filter(struct Qdisc * sch,unsigned long arg)2032 static void htb_unbind_filter(struct Qdisc *sch, unsigned long arg)
2033 {
2034 struct htb_class *cl = (struct htb_class *)arg;
2035
2036 if (cl)
2037 cl->filter_cnt--;
2038 }
2039
htb_walk(struct Qdisc * sch,struct qdisc_walker * arg)2040 static void htb_walk(struct Qdisc *sch, struct qdisc_walker *arg)
2041 {
2042 struct htb_sched *q = qdisc_priv(sch);
2043 struct htb_class *cl;
2044 unsigned int i;
2045
2046 if (arg->stop)
2047 return;
2048
2049 for (i = 0; i < q->clhash.hashsize; i++) {
2050 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
2051 if (arg->count < arg->skip) {
2052 arg->count++;
2053 continue;
2054 }
2055 if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
2056 arg->stop = 1;
2057 return;
2058 }
2059 arg->count++;
2060 }
2061 }
2062 }
2063
2064 static const struct Qdisc_class_ops htb_class_ops = {
2065 .select_queue = htb_select_queue,
2066 .graft = htb_graft,
2067 .leaf = htb_leaf,
2068 .qlen_notify = htb_qlen_notify,
2069 .find = htb_search,
2070 .change = htb_change_class,
2071 .delete = htb_delete,
2072 .walk = htb_walk,
2073 .tcf_block = htb_tcf_block,
2074 .bind_tcf = htb_bind_filter,
2075 .unbind_tcf = htb_unbind_filter,
2076 .dump = htb_dump_class,
2077 .dump_stats = htb_dump_class_stats,
2078 };
2079
2080 static struct Qdisc_ops htb_qdisc_ops __read_mostly = {
2081 .cl_ops = &htb_class_ops,
2082 .id = "htb",
2083 .priv_size = sizeof(struct htb_sched),
2084 .enqueue = htb_enqueue,
2085 .dequeue = htb_dequeue,
2086 .peek = qdisc_peek_dequeued,
2087 .init = htb_init,
2088 .attach = htb_attach,
2089 .reset = htb_reset,
2090 .destroy = htb_destroy,
2091 .dump = htb_dump,
2092 .owner = THIS_MODULE,
2093 };
2094
htb_module_init(void)2095 static int __init htb_module_init(void)
2096 {
2097 return register_qdisc(&htb_qdisc_ops);
2098 }
htb_module_exit(void)2099 static void __exit htb_module_exit(void)
2100 {
2101 unregister_qdisc(&htb_qdisc_ops);
2102 }
2103
2104 module_init(htb_module_init)
2105 module_exit(htb_module_exit)
2106 MODULE_LICENSE("GPL");
2107