aboutsummaryrefslogtreecommitdiff
path: root/include/net/sch_generic.h
blob: d60e7c39d60c72829bde045bd9dcbb6d36d52141 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __NET_SCHED_GENERIC_H
#define __NET_SCHED_GENERIC_H

#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/rcupdate.h>
#include <linux/pkt_sched.h>
#include <linux/pkt_cls.h>
#include <linux/percpu.h>
#include <linux/dynamic_queue_limits.h>
#include <linux/list.h>
#include <linux/refcount.h>
#include <linux/workqueue.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/atomic.h>
#include <linux/hashtable.h>
#include <net/gen_stats.h>
#include <net/rtnetlink.h>
#include <net/flow_offload.h>

struct Qdisc_ops;
struct qdisc_walker;
struct tcf_walker;
struct module;
struct bpf_flow_keys;

struct qdisc_rate_table {
	struct tc_ratespec rate;
	u32		data[256];
	struct qdisc_rate_table *next;
	int		refcnt;
};

enum qdisc_state_t {
	__QDISC_STATE_SCHED,
	__QDISC_STATE_DEACTIVATED,
};

struct qdisc_size_table {
	struct rcu_head		rcu;
	struct list_head	list;
	struct tc_sizespec	szopts;
	int			refcnt;
	u16			data[];
};

/* similar to sk_buff_head, but skb->prev pointer is undefined. */
struct qdisc_skb_head {
	struct sk_buff	*head;
	struct sk_buff	*tail;
	__u32		qlen;
	spinlock_t	lock;
};

struct Qdisc {
	int 			(*enqueue)(struct sk_buff *skb,
					   struct Qdisc *sch,
					   struct sk_buff **to_free);
	struct sk_buff *	(*dequeue)(struct Qdisc *sch);
	unsigned int		flags;
#define TCQ_F_BUILTIN		1
#define TCQ_F_INGRESS		2
#define TCQ_F_CAN_BYPASS	4
#define TCQ_F_MQROOT		8
#define TCQ_F_ONETXQUEUE	0x10 /* dequeue_skb() can assume all skbs are for
				      * q->dev_queue : It can test
				      * netif_xmit_frozen_or_stopped() before
				      * dequeueing next packet.
				      * Its true for MQ/MQPRIO slaves, or non
				      * multiqueue device.
				      */
#define TCQ_F_WARN_NONWC	(1 << 16)
#define TCQ_F_CPUSTATS		0x20 /* run using percpu statistics */
#define TCQ_F_NOPARENT		0x40 /* root of its hierarchy :
				      * qdisc_tree_decrease_qlen() should stop.
				      */
#define TCQ_F_INVISIBLE		0x80 /* invisible by default in dump */
#define TCQ_F_NOLOCK		0x100 /* qdisc does not require locking */
#define TCQ_F_OFFLOADED		0x200 /* qdisc is offloaded to HW */
	u32			limit;
	const struct Qdisc_ops	*ops;
	struct qdisc_size_table	__rcu *stab;
	struct hlist_node       hash;
	u32			handle;
	u32			parent;

	struct netdev_queue	*dev_queue;

	struct net_rate_estimator __rcu *rate_est;
	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
	struct gnet_stats_queue	__percpu *cpu_qstats;
	int			padded;
	refcount_t		refcnt;

	/*
	 * For performance sake on SMP, we put highly modified fields at the end
	 */
	struct sk_buff_head	gso_skb ____cacheline_aligned_in_smp;
	struct qdisc_skb_head	q;
	struct gnet_stats_basic_packed bstats;
	seqcount_t		running;
	struct gnet_stats_queue	qstats;
	unsigned long		state;
	struct Qdisc            *next_sched;
	struct sk_buff_head	skb_bad_txq;

	spinlock_t		busylock ____cacheline_aligned_in_smp;
	spinlock_t		seqlock;

	/* for NOLOCK qdisc, true if there are no enqueued skbs */
	bool			empty;
	struct rcu_head		rcu;
};

static inline void qdisc_refcount_inc(struct Qdisc *qdisc)
{
	if (qdisc->flags & TCQ_F_BUILTIN)
		return;
	refcount_inc(&qdisc->refcnt);
}

/* Intended to be used by unlocked users, when concurrent qdisc release is
 * possible.
 */

static inline struct Qdisc *qdisc_refcount_inc_nz(struct Qdisc *qdisc)
{
	if (qdisc->flags & TCQ_F_BUILTIN)
		return qdisc;
	if (refcount_inc_not_zero(&qdisc->refcnt))
		return qdisc;
	return NULL;
}

static inline bool qdisc_is_running(struct Qdisc *qdisc)
{
	if (qdisc->flags & TCQ_F_NOLOCK)
		return spin_is_locked(&qdisc->seqlock);
	return (raw_read_seqcount(&qdisc->running) & 1) ? true : false;
}

static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
{
	return q->flags & TCQ_F_CPUSTATS;
}

static inline bool qdisc_is_empty(const struct Qdisc *qdisc)
{
	if (qdisc_is_percpu_stats(qdisc))
		return READ_ONCE(qdisc->empty);
	return !READ_ONCE(qdisc->q.qlen);
}

static inline bool qdisc_run_begin(struct Qdisc *qdisc)
{
	if (qdisc->flags & TCQ_F_NOLOCK) {
		if (!spin_trylock(&qdisc->seqlock))
			return false;
		WRITE_ONCE(qdisc->empty, false);
	} else if (qdisc_is_running(qdisc)) {
		return false;
	}
	/* Variant of write_seqcount_begin() telling lockdep a trylock
	 * was attempted.
	 */
	raw_write_seqcount_begin(&qdisc->running);
	seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_);
	return true;
}

static inline void qdisc_run_end(struct Qdisc *qdisc)
{
	write_seqcount_end(&qdisc->running);
	if (qdisc->flags & TCQ_F_NOLOCK)
		spin_unlock(&qdisc->seqlock);
}

static inline bool qdisc_may_bulk(const struct Qdisc *qdisc)
{
	return qdisc->flags & TCQ_F_ONETXQUEUE;
}

static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq)
{
#ifdef CONFIG_BQL
	/* Non-BQL migrated drivers will return 0, too. */
	return dql_avail(&txq->dql);
#else
	return 0;
#endif
}

struct Qdisc_class_ops {
	unsigned int		flags;
	/* Child qdisc manipulation */
	struct netdev_queue *	(*select_queue)(struct Qdisc *, struct tcmsg *);
	int			(*graft)(struct Qdisc *, unsigned long cl,
					struct Qdisc *, struct Qdisc **,
					struct netlink_ext_ack *extack);
	struct Qdisc *		(*leaf)(struct Qdisc *, unsigned long cl);
	void			(*qlen_notify)(struct Qdisc *, unsigned long);

	/* Class manipulation routines */
	unsigned long		(*find)(struct Qdisc *, u32 classid);
	int			(*change)(struct Qdisc *, u32, u32,
					struct nlattr **, unsigned long *,
					struct netlink_ext_ack *);
	int			(*delete)(struct Qdisc *, unsigned long);
	void			(*walk)(struct Qdisc *, struct qdisc_walker * arg);

	/* Filter manipulation */
	struct tcf_block *	(*tcf_block)(struct Qdisc *sch,
					     unsigned long arg,
					     struct netlink_ext_ack *extack);
	unsigned long		(*bind_tcf)(struct Qdisc *, unsigned long,
					u32 classid);
	void			(*unbind_tcf)(struct Qdisc *, unsigned long);

	/* rtnetlink specific */
	int			(*dump)(struct Qdisc *, unsigned long,
					struct sk_buff *skb, struct tcmsg*);
	int			(*dump_stats)(struct Qdisc *, unsigned long,
					struct gnet_dump *);
};

/* Qdisc_class_ops flag values */

/* Implements API that doesn't require rtnl lock */
enum qdisc_class_ops_flags {
	QDISC_CLASS_OPS_DOIT_UNLOCKED = 1,
};

struct Qdisc_ops {
	struct Qdisc_ops	*next;
	const struct Qdisc_class_ops	*cl_ops;
	char			id[IFNAMSIZ];
	int			priv_size;
	unsigned int		static_flags;

	int 			(*enqueue)(struct sk_buff *skb,
					   struct Qdisc *sch,
					   struct sk_buff **to_free);
	struct sk_buff *	(*dequeue)(struct Qdisc *);
	struct sk_buff *	(*peek)(struct Qdisc *);

	int			(*init)(struct Qdisc *sch, struct nlattr *arg,
					struct netlink_ext_ack *extack);
	void			(*reset)(struct Qdisc *);
	void			(*destroy)(struct Qdisc *);
	int			(*change)(struct Qdisc *sch,
					  struct nlattr *arg,
					  struct netlink_ext_ack *extack);
	void			(*attach)(struct Qdisc *sch);
	int			(*change_tx_queue_len)(struct Qdisc *, unsigned int);

	int			(*dump)(struct Qdisc *, struct sk_buff *);
	int			(*dump_stats)(struct Qdisc *, struct gnet_dump *);

	void			(*ingress_block_set)(struct Qdisc *sch,
						     u32 block_index);
	void			(*egress_block_set)(struct Qdisc *sch,
						    u32 block_index);
	u32			(*ingress_block_get)(struct Qdisc *sch);
	u32			(*egress_block_get)(struct Qdisc *sch);

	struct module		*owner;
};


struct tcf_result {
	union {
		struct {
			unsigned long	class;
			u32		classid;
		};
		const struct tcf_proto *goto_tp;

		/* used in the skb_tc_reinsert function */
		struct {
			bool		ingress;
			struct gnet_stats_queue *qstats;
		};
	};
};

struct tcf_chain;

struct tcf_proto_ops {
	struct list_head	head;
	char			kind[IFNAMSIZ];

	int			(*classify)(struct sk_buff *,
					    const struct tcf_proto *,
					    struct tcf_result *);
	int			(*init)(struct tcf_proto*);
	void			(*destroy)(struct tcf_proto *tp, bool rtnl_held,
					   struct netlink_ext_ack *extack);

	void*			(*get)(struct tcf_proto*, u32 handle);
	void			(*put)(struct tcf_proto *tp, void *f);
	int			(*change)(struct net *net, struct sk_buff *,
					struct tcf_proto*, unsigned long,
					u32 handle, struct nlattr **,
					void **, bool, bool,
					struct netlink_ext_ack *);
	int			(*delete)(struct tcf_proto *tp, void *arg,
					  bool *last, bool rtnl_held,
					  struct netlink_ext_ack *);
	bool			(*delete_empty)(struct tcf_proto *tp);
	void			(*walk)(struct tcf_proto *tp,
					struct tcf_walker *arg, bool rtnl_held);
	int			(*reoffload)(struct tcf_proto *tp, bool add,
					     flow_setup_cb_t *cb, void *cb_priv,
					     struct netlink_ext_ack *extack);
	void			(*hw_add)(struct tcf_proto *tp,
					  void *type_data);
	void			(*hw_del)(struct tcf_proto *tp,
					  void *type_data);
	void			(*bind_class)(void *, u32, unsigned long,
					      void *, unsigned long);
	void *			(*tmplt_create)(struct net *net,
						struct tcf_chain *chain,
						struct nlattr **tca,
						struct netlink_ext_ack *extack);
	void			(*tmplt_destroy)(void *tmplt_priv);

	/* rtnetlink specific */
	int			(*dump)(struct net*, struct tcf_proto*, void *,
					struct sk_buff *skb, struct tcmsg*,
					bool);
	int			(*terse_dump)(struct net *net,
					      struct tcf_proto *tp, void *fh,
					      struct sk_buff *skb,
					      struct tcmsg *t, bool rtnl_held);
	int			(*tmplt_dump)(struct sk_buff *skb,
					      struct net *net,
					      void *tmplt_priv);

	struct module		*owner;
	int			flags;
};

/* Classifiers setting TCF_PROTO_OPS_DOIT_UNLOCKED in tcf_proto_ops->flags
 * are expected to implement tcf_proto_ops->delete_empty(), otherwise race
 * conditions can occur when filters are inserted/deleted simultaneously.
 */
enum tcf_proto_ops_flags {
	TCF_PROTO_OPS_DOIT_UNLOCKED = 1,
};

struct tcf_proto {
	/* Fast access part */
	struct tcf_proto __rcu	*next;
	void __rcu		*root;

	/* called under RCU BH lock*/
	int			(*classify)(struct sk_buff *,
					    const struct tcf_proto *,
					    struct tcf_result *);
	__be16			protocol;

	/* All the rest */
	u32			prio;
	void			*data;
	const struct tcf_proto_ops	*ops;
	struct tcf_chain	*chain;
	/* Lock protects tcf_proto shared state and can be used by unlocked
	 * classifiers to protect their private data.
	 */
	spinlock_t		lock;
	bool			deleting;
	refcount_t		refcnt;
	struct rcu_head		rcu;
	struct hlist_node	destroy_ht_node;
};

struct qdisc_skb_cb {
	struct {
		unsigned int		pkt_len;
		u16			slave_dev_queue_mapping;
		u16			tc_classid;
	};
#define QDISC_CB_PRIV_LEN 20
	unsigned char		data[QDISC_CB_PRIV_LEN];
	u16			mru;
};

typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);

struct tcf_chain {
	/* Protects filter_chain. */
	struct mutex filter_chain_lock;
	struct tcf_proto __rcu *filter_chain;
	struct list_head list;
	struct tcf_block *block;
	u32 index; /* chain index */
	unsigned int refcnt;
	unsigned int action_refcnt;
	bool explicitly_created;
	bool flushing;
	const struct tcf_proto_ops *tmplt_ops;
	void *tmplt_priv;
	struct rcu_head rcu;
};

struct tcf_block {
	/* Lock protects tcf_block and lifetime-management data of chains
	 * attached to the block (refcnt, action_refcnt, explicitly_created).
	 */
	struct mutex lock;
	struct list_head chain_list;
	u32 index; /* block index for shared blocks */
	u32 classid; /* which class this block belongs to */
	refcount_t refcnt;
	struct net *net;
	struct Qdisc *q;
	struct rw_semaphore cb_lock; /* protects cb_list and offload counters */
	struct flow_block flow_block;
	struct list_head owner_list;
	bool keep_dst;
	atomic_t offloadcnt; /* Number of oddloaded filters */
	unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */
	unsigned int lockeddevcnt; /* Number of devs that require rtnl lock. */
	struct {
		struct tcf_chain *chain;
		struct list_head filter_chain_list;
	} chain0;
	struct rcu_head rcu;
	DECLARE_HASHTABLE(proto_destroy_ht, 7);
	struct mutex proto_destroy_lock; /* Lock for proto_destroy hashtable. */
};

#ifdef CONFIG_PROVE_LOCKING
static inline bool lockdep_tcf_chain_is_locked(struct tcf_chain *chain)
{
	return lockdep_is_held(&chain->filter_chain_lock);
}

static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
{
	return lockdep_is_held(&tp->lock);
}
#else
static inline bool lockdep_tcf_chain_is_locked(struct tcf_block *chain)
{
	return true;
}

static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
{
	return true;
}
#endif /* #ifdef CONFIG_PROVE_LOCKING */

#define tcf_chain_dereference(p, chain)					\
	rcu_dereference_protected(p, lockdep_tcf_chain_is_locked(chain))

#define tcf_proto_dereference(p, tp)					\
	rcu_dereference_protected(p, lockdep_tcf_proto_is_locked(tp))

static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
{
	struct qdisc_skb_cb *qcb;

	BUILD_BUG_ON(sizeof(skb->cb) < sizeof(*qcb));
	BUILD_BUG_ON(sizeof(qcb->data) < sz);
}

static inline int qdisc_qlen_cpu(const struct Qdisc *q)
{
	return this_cpu_ptr(q->cpu_qstats)->qlen;
}

static inline int qdisc_qlen(const struct Qdisc *q)
{
	return q->q.qlen;
}

static inline int qdisc_qlen_sum(const struct Qdisc *q)
{
	__u32 qlen = q->qstats.qlen;
	int i;

	if (qdisc_is_percpu_stats(q)) {
		for_each_possible_cpu(i)
			qlen += per_cpu_ptr(q->cpu_qstats, i)->qlen;
	} else {
		qlen += q->q.qlen;
	}

	return qlen;
}

static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
{
	return (struct qdisc_skb_cb *)skb->cb;
}

static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
{
	return &qdisc->q.lock;
}

static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
{
	struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);

	return q;
}

static inline struct Qdisc *qdisc_root_bh(const struct Qdisc *qdisc)
{
	return rcu_dereference_bh(qdisc->dev_queue->qdisc);
}

static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
{
	return qdisc->dev_queue->qdisc_sleeping;
}

/* The qdisc root lock is a mechanism by which to top level
 * of a qdisc tree can be locked from any qdisc node in the
 * forest.  This allows changing the configuration of some
 * aspect of the qdisc tree while blocking out asynchronous
 * qdisc access in the packet processing paths.
 *
 * It is only legal to do this when the root will not change
 * on us.  Otherwise we'll potentially lock the wrong qdisc
 * root.  This is enforced by holding the RTNL semaphore, which
 * all users of this lock accessor must do.
 */
static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
{
	struct Qdisc *root = qdisc_root(qdisc);

	ASSERT_RTNL();
	return qdisc_lock(root);
}

static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
{
	struct Qdisc *root = qdisc_root_sleeping(qdisc);

	ASSERT_RTNL();
	return qdisc_lock(root);
}

static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
{
	struct Qdisc *root = qdisc_root_sleeping(qdisc);

	ASSERT_RTNL();
	return &root->running;
}

static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
{
	return qdisc->dev_queue->dev;
}

static inline void sch_tree_lock(const struct Qdisc *q)
{
	spin_lock_bh(qdisc_root_sleeping_lock(q));
}

static inline void sch_tree_unlock(const struct Qdisc *q)
{
	spin_unlock_bh(qdisc_root_sleeping_lock(q));
}

extern struct Qdisc noop_qdisc;
extern struct Qdisc_ops noop_qdisc_ops;
extern struct Qdisc_ops pfifo_fast_ops;
extern struct Qdisc_ops mq_qdisc_ops;
extern struct Qdisc_ops noqueue_qdisc_ops;
extern const struct Qdisc_ops *default_qdisc_ops;
static inline const struct Qdisc_ops *
get_default_qdisc_ops(const struct net_device *dev, int ntx)
{
	return ntx < dev->real_num_tx_queues ?
			default_qdisc_ops : &pfifo_fast_ops;
}

struct Qdisc_class_common {
	u32			classid;
	struct hlist_node	hnode;
};

struct Qdisc_class_hash {
	struct hlist_head	*hash;
	unsigned int		hashsize;
	unsigned int		hashmask;
	unsigned int		hashelems;
};

static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
{
	id ^= id >> 8;
	id ^= id >> 4;
	return id & mask;
}

static inline struct Qdisc_class_common *
qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
{
	struct Qdisc_class_common *cl;
	unsigned int h;

	if (!id)
		return NULL;

	h = qdisc_class_hash(id, hash->hashmask);
	hlist_for_each_entry(cl, &hash->hash[h], hnode) {
		if (cl->classid == id)
			return cl;
	}
	return NULL;
}

static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid)
{
	u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY;

	return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL;
}

int qdisc_class_hash_init(struct Qdisc_class_hash *);
void qdisc_class_hash_insert(struct Qdisc_class_hash *,
			     struct Qdisc_class_common *);
void qdisc_class_hash_remove(struct Qdisc_class_hash *,
			     struct Qdisc_class_common *);
void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
void qdisc_class_hash_destroy(struct Qdisc_class_hash *);

int dev_qdisc_change_tx_queue_len(struct net_device *dev);
void dev_init_scheduler(struct net_device *dev);
void dev_shutdown(struct net_device *dev);
void dev_activate(struct net_device *dev);
void dev_deactivate(struct net_device *dev);
void dev_deactivate_many(struct list_head *head);
struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
			      struct Qdisc *qdisc);
void qdisc_reset(struct Qdisc *qdisc);
void qdisc_put(struct Qdisc *qdisc);
void qdisc_put_unlocked(struct Qdisc *qdisc);
void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, int n, int len);
#ifdef CONFIG_NET_SCHED
int qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
			      void *type_data);
void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
				struct Qdisc *new, struct Qdisc *old,
				enum tc_setup_type type, void *type_data,
				struct netlink_ext_ack *extack);
#else
static inline int
qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
			  void *type_data)
{
	q->flags &= ~TCQ_F_OFFLOADED;
	return 0;
}

static inline void
qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
			   struct Qdisc *new, struct Qdisc *old,
			   enum tc_setup_type type, void *type_data,
			   struct netlink_ext_ack *extack)
{
}
#endif
struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
			  const struct Qdisc_ops *ops,
			  struct netlink_ext_ack *extack);
void qdisc_free(struct Qdisc *qdisc);
struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
				const struct Qdisc_ops *ops, u32 parentid,
				struct netlink_ext_ack *extack);
void __qdisc_calculate_pkt_len(struct sk_buff *skb,
			       const struct qdisc_size_table *stab);
int skb_do_redirect(struct sk_buff *);

static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
{
#ifdef CONFIG_NET_CLS_ACT
	return skb->tc_at_ingress;
#else
	return false;
#endif
}

static inline bool skb_skip_tc_classify(struct sk_buff *skb)
{
#ifdef CONFIG_NET_CLS_ACT
	if (skb->tc_skip_classify) {
		skb->tc_skip_classify = 0;
		return true;
	}
#endif
	return false;
}

/* Reset all TX qdiscs greater than index of a device.  */
static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
{
	struct Qdisc *qdisc;

	for (; i < dev->num_tx_queues; i++) {
		qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
		if (qdisc) {
			spin_lock_bh(qdisc_lock(qdisc));
			qdisc_reset(qdisc);
			spin_unlock_bh(qdisc_lock(qdisc));
		}
	}
}

/* Are all TX queues of the device empty?  */
static inline bool qdisc_all_tx_empty(const struct net_device *dev)
{
	unsigned int i;

	rcu_read_lock();
	for (i = 0; i < dev->num_tx_queues; i++) {
		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
		const struct Qdisc *q = rcu_dereference(txq->qdisc);

		if (!qdisc_is_empty(q)) {
			rcu_read_unlock();
			return false;
		}
	}
	rcu_read_unlock();
	return true;
}

/* Are any of the TX qdiscs changing?  */
static inline bool qdisc_tx_changing(const struct net_device *dev)
{
	unsigned int i;

	for (i = 0; i < dev->num_tx_queues; i++) {
		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
		if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
			return true;
	}
	return false;
}

/* Is the device using the noop qdisc on all queues?  */
static inline bool qdisc_tx_is_noop(const struct net_device *dev)
{
	unsigned int i;

	for (i = 0; i < dev->num_tx_queues; i++) {
		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
		if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
			return false;
	}
	return true;
}

static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
{
	return qdisc_skb_cb(skb)->pkt_len;
}

/* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
enum net_xmit_qdisc_t {
	__NET_XMIT_STOLEN = 0x00010000,
	__NET_XMIT_BYPASS = 0x00020000,
};

#ifdef CONFIG_NET_CLS_ACT
#define net_xmit_drop_count(e)	((e) & __NET_XMIT_STOLEN ? 0 : 1)
#else
#define net_xmit_drop_count(e)	(1)
#endif

static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
					   const struct Qdisc *sch)
{
#ifdef CONFIG_NET_SCHED
	struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);

	if (stab)
		__qdisc_calculate_pkt_len(skb, stab);
#endif
}

static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
				struct sk_buff **to_free)
{
	qdisc_calculate_pkt_len(skb, sch);
	return sch->enqueue(skb, sch, to_free);
}

static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
				  __u64 bytes, __u32 packets)
{
	bstats->bytes += bytes;
	bstats->packets += packets;
}

static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
				 const struct sk_buff *skb)
{
	_bstats_update(bstats,
		       qdisc_pkt_len(skb),
		       skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1);
}

static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
				      __u64 bytes, __u32 packets)
{
	u64_stats_update_begin(&bstats->syncp);
	_bstats_update(&bstats->bstats, bytes, packets);
	u64_stats_update_end(&bstats->syncp);
}

static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
				     const struct sk_buff *skb)
{
	u64_stats_update_begin(&bstats->syncp);
	bstats_update(&bstats->bstats, skb);
	u64_stats_update_end(&bstats->syncp);
}

static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
					   const struct sk_buff *skb)
{
	bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb);
}

static inline void qdisc_bstats_update(struct Qdisc *sch,
				       const struct sk_buff *skb)
{
	bstats_update(&sch->bstats, skb);
}

static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
					    const struct sk_buff *skb)
{
	sch->qstats.backlog -= qdisc_pkt_len(skb);
}

static inline void qdisc_qstats_cpu_backlog_dec(struct Qdisc *sch,
						const struct sk_buff *skb)
{
	this_cpu_sub(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
}

static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
					    const struct sk_buff *skb)
{
	sch->qstats.backlog += qdisc_pkt_len(skb);
}

static inline void qdisc_qstats_cpu_backlog_inc(struct Qdisc *sch,
						const struct sk_buff *skb)
{
	this_cpu_add(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
}

static inline void qdisc_qstats_cpu_qlen_inc(struct Qdisc *sch)
{
	this_cpu_inc(sch->cpu_qstats->qlen);
}

static inline void qdisc_qstats_cpu_qlen_dec(struct Qdisc *sch)
{
	this_cpu_dec(sch->cpu_qstats->qlen);
}

static inline void qdisc_qstats_cpu_requeues_inc(struct Qdisc *sch)
{
	this_cpu_inc(sch->cpu_qstats->requeues);
}

static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
{
	sch->qstats.drops += count;
}

static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
{
	qstats->drops++;
}

static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats)
{
	qstats->overlimits++;
}

static inline void qdisc_qstats_drop(struct Qdisc *sch)
{
	qstats_drop_inc(&sch->qstats);
}

static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
{
	this_cpu_inc(sch->cpu_qstats->drops);
}

static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
{
	sch->qstats.overlimits++;
}

static inline int qdisc_qstats_copy(struct gnet_dump *d, struct Qdisc *sch)
{
	__u32 qlen = qdisc_qlen_sum(sch);

	return gnet_stats_copy_queue(d, sch->cpu_qstats, &sch->qstats, qlen);
}

static inline void qdisc_qstats_qlen_backlog(struct Qdisc *sch,  __u32 *qlen,
					     __u32 *backlog)
{
	struct gnet_stats_queue qstats = { 0 };
	__u32 len = qdisc_qlen_sum(sch);

	__gnet_stats_copy_queue(&qstats, sch->cpu_qstats, &sch->qstats, len);
	*qlen = qstats.qlen;
	*backlog = qstats.backlog;
}

static inline void qdisc_tree_flush_backlog(struct Qdisc *sch)
{
	__u32 qlen, backlog;

	qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
	qdisc_tree_reduce_backlog(sch, qlen, backlog);
}

static inline void qdisc_purge_queue(struct Qdisc *sch)
{
	__u32 qlen, backlog;

	qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
	qdisc_reset(sch);
	qdisc_tree_reduce_backlog(sch, qlen, backlog);
}

static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh)
{
	qh->head = NULL;
	qh->tail = NULL;
	qh->qlen = 0;
}

static inline void __qdisc_enqueue_tail(struct sk_buff *skb,
					struct qdisc_skb_head *qh)
{
	struct sk_buff *last = qh->tail;

	if (last) {
		skb->next = NULL;
		last->next = skb;
		qh->tail = skb;
	} else {
		qh->tail = skb;
		qh->head = skb;
	}
	qh->qlen++;
}

static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
{
	__qdisc_enqueue_tail(skb, &sch->q);
	qdisc_qstats_backlog_inc(sch, skb);
	return NET_XMIT_SUCCESS;
}

static inline void __qdisc_enqueue_head(struct sk_buff *skb,
					struct qdisc_skb_head *qh)
{
	skb->next = qh->head;

	if (!qh->head)
		qh->tail = skb;
	qh->head = skb;
	qh->qlen++;
}

static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh)
{
	struct sk_buff *skb = qh->head;

	if (likely(skb != NULL)) {
		qh->head = skb->next;
		qh->qlen--;
		if (qh->head == NULL)
			qh->tail = NULL;
		skb->next = NULL;
	}

	return skb;
}

static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
{
	struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);

	if (likely(skb != NULL)) {
		qdisc_qstats_backlog_dec(sch, skb);
		qdisc_bstats_update(sch, skb);
	}

	return skb;
}

/* Instead of calling kfree_skb() while root qdisc lock is held,
 * queue the skb for future freeing at end of __dev_xmit_skb()
 */
static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free)
{
	skb->next = *to_free;
	*to_free = skb;
}

static inline void __qdisc_drop_all(struct sk_buff *skb,
				    struct sk_buff **to_free)
{
	if (skb->prev)
		skb->prev->next = *to_free;
	else
		skb->next = *to_free;
	*to_free = skb;
}

static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
						   struct qdisc_skb_head *qh,
						   struct sk_buff **to_free)
{
	struct sk_buff *skb = __qdisc_dequeue_head(qh);

	if (likely(skb != NULL)) {
		unsigned int len = qdisc_pkt_len(skb);

		qdisc_qstats_backlog_dec(sch, skb);
		__qdisc_drop(skb, to_free);
		return len;
	}

	return 0;
}

static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch,
						 struct sk_buff **to_free)
{
	return __qdisc_queue_drop_head(sch, &sch->q, to_free);
}

static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
{
	const struct qdisc_skb_head *qh = &sch->q;

	return qh->head;
}

/* generic pseudo peek method for non-work-conserving qdisc */
static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
{
	struct sk_buff *skb = skb_peek(&sch->gso_skb);

	/* we can reuse ->gso_skb because peek isn't called for root qdiscs */
	if (!skb) {
		skb = sch->dequeue(sch);

		if (skb) {
			__skb_queue_head(&sch->gso_skb, skb);
			/* it's still part of the queue */
			qdisc_qstats_backlog_inc(sch, skb);
			sch->q.qlen++;
		}
	}

	return skb;
}

static inline void qdisc_update_stats_at_dequeue(struct Qdisc *sch,
						 struct sk_buff *skb)
{
	if (qdisc_is_percpu_stats(sch)) {
		qdisc_qstats_cpu_backlog_dec(sch, skb);
		qdisc_bstats_cpu_update(sch, skb);
		qdisc_qstats_cpu_qlen_dec(sch);
	} else {
		qdisc_qstats_backlog_dec(sch, skb);
		qdisc_bstats_update(sch, skb);
		sch->q.qlen--;
	}
}

static inline void qdisc_update_stats_at_enqueue(struct Qdisc *sch,
						 unsigned int pkt_len)
{
	if (qdisc_is_percpu_stats(sch)) {
		qdisc_qstats_cpu_qlen_inc(sch);
		this_cpu_add(sch->cpu_qstats->backlog, pkt_len);
	} else {
		sch->qstats.backlog += pkt_len;
		sch->q.qlen++;
	}
}

/* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
{
	struct sk_buff *skb = skb_peek(&sch->gso_skb);

	if (skb) {
		skb = __skb_dequeue(&sch->gso_skb);
		if (qdisc_is_percpu_stats(sch)) {
			qdisc_qstats_cpu_backlog_dec(sch, skb);
			qdisc_qstats_cpu_qlen_dec(sch);
		} else {
			qdisc_qstats_backlog_dec(sch, skb);
			sch->q.qlen--;
		}
	} else {
		skb = sch->dequeue(sch);
	}

	return skb;
}

static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh)
{
	/*
	 * We do not know the backlog in bytes of this list, it
	 * is up to the caller to correct it
	 */
	ASSERT_RTNL();
	if (qh->qlen) {
		rtnl_kfree_skbs(qh->head, qh->tail);

		qh->head = NULL;
		qh->tail = NULL;
		qh->qlen = 0;
	}
}

static inline void qdisc_reset_queue(struct Qdisc *sch)
{
	__qdisc_reset_queue(&sch->q);
	sch->qstats.backlog = 0;
}

static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
					  struct Qdisc **pold)
{
	struct Qdisc *old;

	sch_tree_lock(sch);
	old = *pold;
	*pold = new;
	if (old != NULL)
		qdisc_tree_flush_backlog(old);
	sch_tree_unlock(sch);

	return old;
}

static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
{
	rtnl_kfree_skbs(skb, skb);
	qdisc_qstats_drop(sch);
}

static inline int qdisc_drop_cpu(struct sk_buff *skb, struct Qdisc *sch,
				 struct sk_buff **to_free)
{
	__qdisc_drop(skb, to_free);
	qdisc_qstats_cpu_drop(sch);

	return NET_XMIT_DROP;
}

static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch,
			     struct sk_buff **to_free)
{
	__qdisc_drop(skb, to_free);
	qdisc_qstats_drop(sch);

	return NET_XMIT_DROP;
}

static inline int qdisc_drop_all(struct sk_buff *skb, struct Qdisc *sch,
				 struct sk_buff **to_free)
{
	__qdisc_drop_all(skb, to_free);
	qdisc_qstats_drop(sch);

	return NET_XMIT_DROP;
}

/* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
   long it will take to send a packet given its size.
 */
static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
{
	int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
	if (slot < 0)
		slot = 0;
	slot >>= rtab->rate.cell_log;
	if (slot > 255)
		return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
	return rtab->data[slot];
}

struct psched_ratecfg {
	u64	rate_bytes_ps; /* bytes per second */
	u32	mult;
	u16	overhead;
	u8	linklayer;
	u8	shift;
};

static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
				unsigned int len)
{
	len += r->overhead;

	if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
		return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;

	return ((u64)len * r->mult) >> r->shift;
}

void psched_ratecfg_precompute(struct psched_ratecfg *r,
			       const struct tc_ratespec *conf,
			       u64 rate64);

static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
					  const struct psched_ratecfg *r)
{
	memset(res, 0, sizeof(*res));

	/* legacy struct tc_ratespec has a 32bit @rate field
	 * Qdisc using 64bit rate should add new attributes
	 * in order to maintain compatibility.
	 */
	res->rate = min_t(u64, r->rate_bytes_ps, ~0U);

	res->overhead = r->overhead;
	res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
}

/* Mini Qdisc serves for specific needs of ingress/clsact Qdisc.
 * The fast path only needs to access filter list and to update stats
 */
struct mini_Qdisc {
	struct tcf_proto *filter_list;
	struct tcf_block *block;
	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
	struct gnet_stats_queue	__percpu *cpu_qstats;
	struct rcu_head rcu;
};

static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq,
						const struct sk_buff *skb)
{
	bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb);
}

static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq)
{
	this_cpu_inc(miniq->cpu_qstats->drops);
}

struct mini_Qdisc_pair {
	struct mini_Qdisc miniq1;
	struct mini_Qdisc miniq2;
	struct mini_Qdisc __rcu **p_miniq;
};

void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
			  struct tcf_proto *tp_head);
void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
			  struct mini_Qdisc __rcu **p_miniq);
void mini_qdisc_pair_block_init(struct mini_Qdisc_pair *miniqp,
				struct tcf_block *block);

static inline int skb_tc_reinsert(struct sk_buff *skb, struct tcf_result *res)
{
	return res->ingress ? netif_receive_skb(skb) : dev_queue_xmit(skb);
}

#endif