summaryrefslogtreecommitdiff
path: root/net/bridge/br_cfm.c
blob: 001064f7583d4541f6dae156b88d48130d5f4e7a (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
// SPDX-License-Identifier: GPL-2.0-or-later

#include <linux/cfm_bridge.h>
#include <uapi/linux/cfm_bridge.h>
#include "br_private_cfm.h"

static struct br_cfm_mep *br_mep_find(struct net_bridge *br, u32 instance)
{
	struct br_cfm_mep *mep;

	hlist_for_each_entry(mep, &br->mep_list, head)
		if (mep->instance == instance)
			return mep;

	return NULL;
}

static struct br_cfm_mep *br_mep_find_ifindex(struct net_bridge *br,
					      u32 ifindex)
{
	struct br_cfm_mep *mep;

	hlist_for_each_entry_rcu(mep, &br->mep_list, head,
				 lockdep_rtnl_is_held())
		if (mep->create.ifindex == ifindex)
			return mep;

	return NULL;
}

static struct br_cfm_peer_mep *br_peer_mep_find(struct br_cfm_mep *mep,
						u32 mepid)
{
	struct br_cfm_peer_mep *peer_mep;

	hlist_for_each_entry_rcu(peer_mep, &mep->peer_mep_list, head,
				 lockdep_rtnl_is_held())
		if (peer_mep->mepid == mepid)
			return peer_mep;

	return NULL;
}

static struct net_bridge_port *br_mep_get_port(struct net_bridge *br,
					       u32 ifindex)
{
	struct net_bridge_port *port;

	list_for_each_entry(port, &br->port_list, list)
		if (port->dev->ifindex == ifindex)
			return port;

	return NULL;
}

/* Calculate the CCM interval in us. */
static u32 interval_to_us(enum br_cfm_ccm_interval interval)
{
	switch (interval) {
	case BR_CFM_CCM_INTERVAL_NONE:
		return 0;
	case BR_CFM_CCM_INTERVAL_3_3_MS:
		return 3300;
	case BR_CFM_CCM_INTERVAL_10_MS:
		return 10 * 1000;
	case BR_CFM_CCM_INTERVAL_100_MS:
		return 100 * 1000;
	case BR_CFM_CCM_INTERVAL_1_SEC:
		return 1000 * 1000;
	case BR_CFM_CCM_INTERVAL_10_SEC:
		return 10 * 1000 * 1000;
	case BR_CFM_CCM_INTERVAL_1_MIN:
		return 60 * 1000 * 1000;
	case BR_CFM_CCM_INTERVAL_10_MIN:
		return 10 * 60 * 1000 * 1000;
	}
	return 0;
}

/* Convert the interface interval to CCM PDU value. */
static u32 interval_to_pdu(enum br_cfm_ccm_interval interval)
{
	switch (interval) {
	case BR_CFM_CCM_INTERVAL_NONE:
		return 0;
	case BR_CFM_CCM_INTERVAL_3_3_MS:
		return 1;
	case BR_CFM_CCM_INTERVAL_10_MS:
		return 2;
	case BR_CFM_CCM_INTERVAL_100_MS:
		return 3;
	case BR_CFM_CCM_INTERVAL_1_SEC:
		return 4;
	case BR_CFM_CCM_INTERVAL_10_SEC:
		return 5;
	case BR_CFM_CCM_INTERVAL_1_MIN:
		return 6;
	case BR_CFM_CCM_INTERVAL_10_MIN:
		return 7;
	}
	return 0;
}

/* Convert the CCM PDU value to interval on interface. */
static u32 pdu_to_interval(u32 value)
{
	switch (value) {
	case 0:
		return BR_CFM_CCM_INTERVAL_NONE;
	case 1:
		return BR_CFM_CCM_INTERVAL_3_3_MS;
	case 2:
		return BR_CFM_CCM_INTERVAL_10_MS;
	case 3:
		return BR_CFM_CCM_INTERVAL_100_MS;
	case 4:
		return BR_CFM_CCM_INTERVAL_1_SEC;
	case 5:
		return BR_CFM_CCM_INTERVAL_10_SEC;
	case 6:
		return BR_CFM_CCM_INTERVAL_1_MIN;
	case 7:
		return BR_CFM_CCM_INTERVAL_10_MIN;
	}
	return BR_CFM_CCM_INTERVAL_NONE;
}

static void ccm_rx_timer_start(struct br_cfm_peer_mep *peer_mep)
{
	u32 interval_us;

	interval_us = interval_to_us(peer_mep->mep->cc_config.exp_interval);
	/* Function ccm_rx_dwork must be called with 1/4
	 * of the configured CC 'expected_interval'
	 * in order to detect CCM defect after 3.25 interval.
	 */
	queue_delayed_work(system_wq, &peer_mep->ccm_rx_dwork,
			   usecs_to_jiffies(interval_us / 4));
}

static void br_cfm_notify(int event, const struct net_bridge_port *port)
{
	u32 filter = RTEXT_FILTER_CFM_STATUS;

	return br_info_notify(event, port->br, NULL, filter);
}

static void cc_peer_enable(struct br_cfm_peer_mep *peer_mep)
{
	memset(&peer_mep->cc_status, 0, sizeof(peer_mep->cc_status));
	peer_mep->ccm_rx_count_miss = 0;

	ccm_rx_timer_start(peer_mep);
}

static void cc_peer_disable(struct br_cfm_peer_mep *peer_mep)
{
	cancel_delayed_work_sync(&peer_mep->ccm_rx_dwork);
}

static struct sk_buff *ccm_frame_build(struct br_cfm_mep *mep,
				       const struct br_cfm_cc_ccm_tx_info *const tx_info)

{
	struct br_cfm_common_hdr *common_hdr;
	struct net_bridge_port *b_port;
	struct br_cfm_maid *maid;
	u8 *itu_reserved, *e_tlv;
	struct ethhdr *eth_hdr;
	struct sk_buff *skb;
	__be32 *status_tlv;
	__be32 *snumber;
	__be16 *mepid;

	skb = dev_alloc_skb(CFM_CCM_MAX_FRAME_LENGTH);
	if (!skb)
		return NULL;

	rcu_read_lock();
	b_port = rcu_dereference(mep->b_port);
	if (!b_port) {
		kfree_skb(skb);
		rcu_read_unlock();
		return NULL;
	}
	skb->dev = b_port->dev;
	rcu_read_unlock();
	/* The device cannot be deleted until the work_queue functions has
	 * completed. This function is called from ccm_tx_work_expired()
	 * that is a work_queue functions.
	 */

	skb->protocol = htons(ETH_P_CFM);
	skb->priority = CFM_FRAME_PRIO;

	/* Ethernet header */
	eth_hdr = skb_put(skb, sizeof(*eth_hdr));
	ether_addr_copy(eth_hdr->h_dest, tx_info->dmac.addr);
	ether_addr_copy(eth_hdr->h_source, mep->config.unicast_mac.addr);
	eth_hdr->h_proto = htons(ETH_P_CFM);

	/* Common CFM Header */
	common_hdr = skb_put(skb, sizeof(*common_hdr));
	common_hdr->mdlevel_version = mep->config.mdlevel << 5;
	common_hdr->opcode = BR_CFM_OPCODE_CCM;
	common_hdr->flags = (mep->rdi << 7) |
			    interval_to_pdu(mep->cc_config.exp_interval);
	common_hdr->tlv_offset = CFM_CCM_TLV_OFFSET;

	/* Sequence number */
	snumber = skb_put(skb, sizeof(*snumber));
	if (tx_info->seq_no_update) {
		*snumber = cpu_to_be32(mep->ccm_tx_snumber);
		mep->ccm_tx_snumber += 1;
	} else {
		*snumber = 0;
	}

	mepid = skb_put(skb, sizeof(*mepid));
	*mepid = cpu_to_be16((u16)mep->config.mepid);

	maid = skb_put(skb, sizeof(*maid));
	memcpy(maid->data, mep->cc_config.exp_maid.data, sizeof(maid->data));

	/* ITU reserved (CFM_CCM_ITU_RESERVED_SIZE octets) */
	itu_reserved = skb_put(skb, CFM_CCM_ITU_RESERVED_SIZE);
	memset(itu_reserved, 0, CFM_CCM_ITU_RESERVED_SIZE);

	/* Generel CFM TLV format:
	 * TLV type:		one byte
	 * TLV value length:	two bytes
	 * TLV value:		'TLV value length' bytes
	 */

	/* Port status TLV. The value length is 1. Total of 4 bytes. */
	if (tx_info->port_tlv) {
		status_tlv = skb_put(skb, sizeof(*status_tlv));
		*status_tlv = cpu_to_be32((CFM_PORT_STATUS_TLV_TYPE << 24) |
					  (1 << 8) |	/* Value length */
					  (tx_info->port_tlv_value & 0xFF));
	}

	/* Interface status TLV. The value length is 1. Total of 4 bytes. */
	if (tx_info->if_tlv) {
		status_tlv = skb_put(skb, sizeof(*status_tlv));
		*status_tlv = cpu_to_be32((CFM_IF_STATUS_TLV_TYPE << 24) |
					  (1 << 8) |	/* Value length */
					  (tx_info->if_tlv_value & 0xFF));
	}

	/* End TLV */
	e_tlv = skb_put(skb, sizeof(*e_tlv));
	*e_tlv = CFM_ENDE_TLV_TYPE;

	return skb;
}

static void ccm_frame_tx(struct sk_buff *skb)
{
	skb_reset_network_header(skb);
	dev_queue_xmit(skb);
}

/* This function is called with the configured CC 'expected_interval'
 * in order to drive CCM transmission when enabled.
 */
static void ccm_tx_work_expired(struct work_struct *work)
{
	struct delayed_work *del_work;
	struct br_cfm_mep *mep;
	struct sk_buff *skb;
	u32 interval_us;

	del_work = to_delayed_work(work);
	mep = container_of(del_work, struct br_cfm_mep, ccm_tx_dwork);

	if (time_before_eq(mep->ccm_tx_end, jiffies)) {
		/* Transmission period has ended */
		mep->cc_ccm_tx_info.period = 0;
		return;
	}

	skb = ccm_frame_build(mep, &mep->cc_ccm_tx_info);
	if (skb)
		ccm_frame_tx(skb);

	interval_us = interval_to_us(mep->cc_config.exp_interval);
	queue_delayed_work(system_wq, &mep->ccm_tx_dwork,
			   usecs_to_jiffies(interval_us));
}

/* This function is called with 1/4 of the configured CC 'expected_interval'
 * in order to detect CCM defect after 3.25 interval.
 */
static void ccm_rx_work_expired(struct work_struct *work)
{
	struct br_cfm_peer_mep *peer_mep;
	struct net_bridge_port *b_port;
	struct delayed_work *del_work;

	del_work = to_delayed_work(work);
	peer_mep = container_of(del_work, struct br_cfm_peer_mep, ccm_rx_dwork);

	/* After 13 counts (4 * 3,25) then 3.25 intervals are expired */
	if (peer_mep->ccm_rx_count_miss < 13) {
		/* 3.25 intervals are NOT expired without CCM reception */
		peer_mep->ccm_rx_count_miss++;

		/* Start timer again */
		ccm_rx_timer_start(peer_mep);
	} else {
		/* 3.25 intervals are expired without CCM reception.
		 * CCM defect detected
		 */
		peer_mep->cc_status.ccm_defect = true;

		/* Change in CCM defect status - notify */
		rcu_read_lock();
		b_port = rcu_dereference(peer_mep->mep->b_port);
		if (b_port)
			br_cfm_notify(RTM_NEWLINK, b_port);
		rcu_read_unlock();
	}
}

static u32 ccm_tlv_extract(struct sk_buff *skb, u32 index,
			   struct br_cfm_peer_mep *peer_mep)
{
	__be32 *s_tlv;
	__be32 _s_tlv;
	u32 h_s_tlv;
	u8 *e_tlv;
	u8 _e_tlv;

	e_tlv = skb_header_pointer(skb, index, sizeof(_e_tlv), &_e_tlv);
	if (!e_tlv)
		return 0;

	/* TLV is present - get the status TLV */
	s_tlv = skb_header_pointer(skb,
				   index,
				   sizeof(_s_tlv), &_s_tlv);
	if (!s_tlv)
		return 0;

	h_s_tlv = ntohl(*s_tlv);
	if ((h_s_tlv >> 24) == CFM_IF_STATUS_TLV_TYPE) {
		/* Interface status TLV */
		peer_mep->cc_status.tlv_seen = true;
		peer_mep->cc_status.if_tlv_value = (h_s_tlv & 0xFF);
	}

	if ((h_s_tlv >> 24) == CFM_PORT_STATUS_TLV_TYPE) {
		/* Port status TLV */
		peer_mep->cc_status.tlv_seen = true;
		peer_mep->cc_status.port_tlv_value = (h_s_tlv & 0xFF);
	}

	/* The Sender ID TLV is not handled */
	/* The Organization-Specific TLV is not handled */

	/* Return the length of this tlv.
	 * This is the length of the value field plus 3 bytes for size of type
	 * field and length field
	 */
	return ((h_s_tlv >> 8) & 0xFFFF) + 3;
}

/* note: already called with rcu_read_lock */
static int br_cfm_frame_rx(struct net_bridge_port *port, struct sk_buff *skb)
{
	u32 mdlevel, interval, size, index, max;
	const struct br_cfm_common_hdr *hdr;
	struct br_cfm_peer_mep *peer_mep;
	const struct br_cfm_maid *maid;
	struct br_cfm_common_hdr _hdr;
	struct br_cfm_maid _maid;
	struct br_cfm_mep *mep;
	struct net_bridge *br;
	__be32 *snumber;
	__be32 _snumber;
	__be16 *mepid;
	__be16 _mepid;

	if (port->state == BR_STATE_DISABLED)
		return 0;

	hdr = skb_header_pointer(skb, 0, sizeof(_hdr), &_hdr);
	if (!hdr)
		return 1;

	br = port->br;
	mep = br_mep_find_ifindex(br, port->dev->ifindex);
	if (unlikely(!mep))
		/* No MEP on this port - must be forwarded */
		return 0;

	mdlevel = hdr->mdlevel_version >> 5;
	if (mdlevel > mep->config.mdlevel)
		/* The level is above this MEP level - must be forwarded */
		return 0;

	if ((hdr->mdlevel_version & 0x1F) != 0) {
		/* Invalid version */
		mep->status.version_unexp_seen = true;
		return 1;
	}

	if (mdlevel < mep->config.mdlevel) {
		/* The level is below this MEP level */
		mep->status.rx_level_low_seen = true;
		return 1;
	}

	if (hdr->opcode == BR_CFM_OPCODE_CCM) {
		/* CCM PDU received. */
		/* MA ID is after common header + sequence number + MEP ID */
		maid = skb_header_pointer(skb,
					  CFM_CCM_PDU_MAID_OFFSET,
					  sizeof(_maid), &_maid);
		if (!maid)
			return 1;
		if (memcmp(maid->data, mep->cc_config.exp_maid.data,
			   sizeof(maid->data)))
			/* MA ID not as expected */
			return 1;

		/* MEP ID is after common header + sequence number */
		mepid = skb_header_pointer(skb,
					   CFM_CCM_PDU_MEPID_OFFSET,
					   sizeof(_mepid), &_mepid);
		if (!mepid)
			return 1;
		peer_mep = br_peer_mep_find(mep, (u32)ntohs(*mepid));
		if (!peer_mep)
			return 1;

		/* Interval is in common header flags */
		interval = hdr->flags & 0x07;
		if (mep->cc_config.exp_interval != pdu_to_interval(interval))
			/* Interval not as expected */
			return 1;

		/* A valid CCM frame is received */
		if (peer_mep->cc_status.ccm_defect) {
			peer_mep->cc_status.ccm_defect = false;

			/* Change in CCM defect status - notify */
			br_cfm_notify(RTM_NEWLINK, port);

			/* Start CCM RX timer */
			ccm_rx_timer_start(peer_mep);
		}

		peer_mep->cc_status.seen = true;
		peer_mep->ccm_rx_count_miss = 0;

		/* RDI is in common header flags */
		peer_mep->cc_status.rdi = (hdr->flags & 0x80) ? true : false;

		/* Sequence number is after common header */
		snumber = skb_header_pointer(skb,
					     CFM_CCM_PDU_SEQNR_OFFSET,
					     sizeof(_snumber), &_snumber);
		if (!snumber)
			return 1;
		if (ntohl(*snumber) != (mep->ccm_rx_snumber + 1))
			/* Unexpected sequence number */
			peer_mep->cc_status.seq_unexp_seen = true;

		mep->ccm_rx_snumber = ntohl(*snumber);

		/* TLV end is after common header + sequence number + MEP ID +
		 * MA ID + ITU reserved
		 */
		index = CFM_CCM_PDU_TLV_OFFSET;
		max = 0;
		do { /* Handle all TLVs */
			size = ccm_tlv_extract(skb, index, peer_mep);
			index += size;
			max += 1;
		} while (size != 0 && max < 4); /* Max four TLVs possible */

		return 1;
	}

	mep->status.opcode_unexp_seen = true;

	return 1;
}

static struct br_frame_type cfm_frame_type __read_mostly = {
	.type = cpu_to_be16(ETH_P_CFM),
	.frame_handler = br_cfm_frame_rx,
};

int br_cfm_mep_create(struct net_bridge *br,
		      const u32 instance,
		      struct br_cfm_mep_create *const create,
		      struct netlink_ext_ack *extack)
{
	struct net_bridge_port *p;
	struct br_cfm_mep *mep;

	ASSERT_RTNL();

	if (create->domain == BR_CFM_VLAN) {
		NL_SET_ERR_MSG_MOD(extack,
				   "VLAN domain not supported");
		return -EINVAL;
	}
	if (create->domain != BR_CFM_PORT) {
		NL_SET_ERR_MSG_MOD(extack,
				   "Invalid domain value");
		return -EINVAL;
	}
	if (create->direction == BR_CFM_MEP_DIRECTION_UP) {
		NL_SET_ERR_MSG_MOD(extack,
				   "Up-MEP not supported");
		return -EINVAL;
	}
	if (create->direction != BR_CFM_MEP_DIRECTION_DOWN) {
		NL_SET_ERR_MSG_MOD(extack,
				   "Invalid direction value");
		return -EINVAL;
	}
	p = br_mep_get_port(br, create->ifindex);
	if (!p) {
		NL_SET_ERR_MSG_MOD(extack,
				   "Port is not related to bridge");
		return -EINVAL;
	}
	mep = br_mep_find(br, instance);
	if (mep) {
		NL_SET_ERR_MSG_MOD(extack,
				   "MEP instance already exists");
		return -EEXIST;
	}

	/* In PORT domain only one instance can be created per port */
	if (create->domain == BR_CFM_PORT) {
		mep = br_mep_find_ifindex(br, create->ifindex);
		if (mep) {
			NL_SET_ERR_MSG_MOD(extack,
					   "Only one Port MEP on a port allowed");
			return -EINVAL;
		}
	}

	mep = kzalloc(sizeof(*mep), GFP_KERNEL);
	if (!mep)
		return -ENOMEM;

	mep->create = *create;
	mep->instance = instance;
	rcu_assign_pointer(mep->b_port, p);

	INIT_HLIST_HEAD(&mep->peer_mep_list);
	INIT_DELAYED_WORK(&mep->ccm_tx_dwork, ccm_tx_work_expired);

	if (hlist_empty(&br->mep_list))
		br_add_frame(br, &cfm_frame_type);

	hlist_add_tail_rcu(&mep->head, &br->mep_list);

	return 0;
}

static void mep_delete_implementation(struct net_bridge *br,
				      struct br_cfm_mep *mep)
{
	struct br_cfm_peer_mep *peer_mep;
	struct hlist_node *n_store;

	ASSERT_RTNL();

	/* Empty and free peer MEP list */
	hlist_for_each_entry_safe(peer_mep, n_store, &mep->peer_mep_list, head) {
		cancel_delayed_work_sync(&peer_mep->ccm_rx_dwork);
		hlist_del_rcu(&peer_mep->head);
		kfree_rcu(peer_mep, rcu);
	}

	cancel_delayed_work_sync(&mep->ccm_tx_dwork);

	RCU_INIT_POINTER(mep->b_port, NULL);
	hlist_del_rcu(&mep->head);
	kfree_rcu(mep, rcu);

	if (hlist_empty(&br->mep_list))
		br_del_frame(br, &cfm_frame_type);
}

int br_cfm_mep_delete(struct net_bridge *br,
		      const u32 instance,
		      struct netlink_ext_ack *extack)
{
	struct br_cfm_mep *mep;

	ASSERT_RTNL();

	mep = br_mep_find(br, instance);
	if (!mep) {
		NL_SET_ERR_MSG_MOD(extack,
				   "MEP instance does not exists");
		return -ENOENT;
	}

	mep_delete_implementation(br, mep);

	return 0;
}

int br_cfm_mep_config_set(struct net_bridge *br,
			  const u32 instance,
			  const struct br_cfm_mep_config *const config,
			  struct netlink_ext_ack *extack)
{
	struct br_cfm_mep *mep;

	ASSERT_RTNL();

	mep = br_mep_find(br, instance);
	if (!mep) {
		NL_SET_ERR_MSG_MOD(extack,
				   "MEP instance does not exists");
		return -ENOENT;
	}

	mep->config = *config;

	return 0;
}

int br_cfm_cc_config_set(struct net_bridge *br,
			 const u32 instance,
			 const struct br_cfm_cc_config *const config,
			 struct netlink_ext_ack *extack)
{
	struct br_cfm_peer_mep *peer_mep;
	struct br_cfm_mep *mep;

	ASSERT_RTNL();

	mep = br_mep_find(br, instance);
	if (!mep) {
		NL_SET_ERR_MSG_MOD(extack,
				   "MEP instance does not exists");
		return -ENOENT;
	}

	/* Check for no change in configuration */
	if (memcmp(config, &mep->cc_config, sizeof(*config)) == 0)
		return 0;

	if (config->enable && !mep->cc_config.enable)
		/* CC is enabled */
		hlist_for_each_entry(peer_mep, &mep->peer_mep_list, head)
			cc_peer_enable(peer_mep);

	if (!config->enable && mep->cc_config.enable)
		/* CC is disabled */
		hlist_for_each_entry(peer_mep, &mep->peer_mep_list, head)
			cc_peer_disable(peer_mep);

	mep->cc_config = *config;
	mep->ccm_rx_snumber = 0;
	mep->ccm_tx_snumber = 1;

	return 0;
}

int br_cfm_cc_peer_mep_add(struct net_bridge *br, const u32 instance,
			   u32 mepid,
			   struct netlink_ext_ack *extack)
{
	struct br_cfm_peer_mep *peer_mep;
	struct br_cfm_mep *mep;

	ASSERT_RTNL();

	mep = br_mep_find(br, instance);
	if (!mep) {
		NL_SET_ERR_MSG_MOD(extack,
				   "MEP instance does not exists");
		return -ENOENT;
	}

	peer_mep = br_peer_mep_find(mep, mepid);
	if (peer_mep) {
		NL_SET_ERR_MSG_MOD(extack,
				   "Peer MEP-ID already exists");
		return -EEXIST;
	}

	peer_mep = kzalloc(sizeof(*peer_mep), GFP_KERNEL);
	if (!peer_mep)
		return -ENOMEM;

	peer_mep->mepid = mepid;
	peer_mep->mep = mep;
	INIT_DELAYED_WORK(&peer_mep->ccm_rx_dwork, ccm_rx_work_expired);

	if (mep->cc_config.enable)
		cc_peer_enable(peer_mep);

	hlist_add_tail_rcu(&peer_mep->head, &mep->peer_mep_list);

	return 0;
}

int br_cfm_cc_peer_mep_remove(struct net_bridge *br, const u32 instance,
			      u32 mepid,
			      struct netlink_ext_ack *extack)
{
	struct br_cfm_peer_mep *peer_mep;
	struct br_cfm_mep *mep;

	ASSERT_RTNL();

	mep = br_mep_find(br, instance);
	if (!mep) {
		NL_SET_ERR_MSG_MOD(extack,
				   "MEP instance does not exists");
		return -ENOENT;
	}

	peer_mep = br_peer_mep_find(mep, mepid);
	if (!peer_mep) {
		NL_SET_ERR_MSG_MOD(extack,
				   "Peer MEP-ID does not exists");
		return -ENOENT;
	}

	cc_peer_disable(peer_mep);

	hlist_del_rcu(&peer_mep->head);
	kfree_rcu(peer_mep, rcu);

	return 0;
}

int br_cfm_cc_rdi_set(struct net_bridge *br, const u32 instance,
		      const bool rdi, struct netlink_ext_ack *extack)
{
	struct br_cfm_mep *mep;

	ASSERT_RTNL();

	mep = br_mep_find(br, instance);
	if (!mep) {
		NL_SET_ERR_MSG_MOD(extack,
				   "MEP instance does not exists");
		return -ENOENT;
	}

	mep->rdi = rdi;

	return 0;
}

int br_cfm_cc_ccm_tx(struct net_bridge *br, const u32 instance,
		     const struct br_cfm_cc_ccm_tx_info *const tx_info,
		     struct netlink_ext_ack *extack)
{
	struct br_cfm_mep *mep;

	ASSERT_RTNL();

	mep = br_mep_find(br, instance);
	if (!mep) {
		NL_SET_ERR_MSG_MOD(extack,
				   "MEP instance does not exists");
		return -ENOENT;
	}

	if (memcmp(tx_info, &mep->cc_ccm_tx_info, sizeof(*tx_info)) == 0) {
		/* No change in tx_info. */
		if (mep->cc_ccm_tx_info.period == 0)
			/* Transmission is not enabled - just return */
			return 0;

		/* Transmission is ongoing, the end time is recalculated */
		mep->ccm_tx_end = jiffies +
				  usecs_to_jiffies(tx_info->period * 1000000);
		return 0;
	}

	if (tx_info->period == 0 && mep->cc_ccm_tx_info.period == 0)
		/* Some change in info and transmission is not ongoing */
		goto save;

	if (tx_info->period != 0 && mep->cc_ccm_tx_info.period != 0) {
		/* Some change in info and transmission is ongoing
		 * The end time is recalculated
		 */
		mep->ccm_tx_end = jiffies +
				  usecs_to_jiffies(tx_info->period * 1000000);

		goto save;
	}

	if (tx_info->period == 0 && mep->cc_ccm_tx_info.period != 0) {
		cancel_delayed_work_sync(&mep->ccm_tx_dwork);
		goto save;
	}

	/* Start delayed work to transmit CCM frames. It is done with zero delay
	 * to send first frame immediately
	 */
	mep->ccm_tx_end = jiffies + usecs_to_jiffies(tx_info->period * 1000000);
	queue_delayed_work(system_wq, &mep->ccm_tx_dwork, 0);

save:
	mep->cc_ccm_tx_info = *tx_info;

	return 0;
}

int br_cfm_mep_count(struct net_bridge *br, u32 *count)
{
	struct br_cfm_mep *mep;

	*count = 0;

	rcu_read_lock();
	hlist_for_each_entry_rcu(mep, &br->mep_list, head)
		*count += 1;
	rcu_read_unlock();

	return 0;
}

int br_cfm_peer_mep_count(struct net_bridge *br, u32 *count)
{
	struct br_cfm_peer_mep *peer_mep;
	struct br_cfm_mep *mep;

	*count = 0;

	rcu_read_lock();
	hlist_for_each_entry_rcu(mep, &br->mep_list, head)
		hlist_for_each_entry_rcu(peer_mep, &mep->peer_mep_list, head)
			*count += 1;
	rcu_read_unlock();

	return 0;
}

bool br_cfm_created(struct net_bridge *br)
{
	return !hlist_empty(&br->mep_list);
}

/* Deletes the CFM instances on a specific bridge port
 */
void br_cfm_port_del(struct net_bridge *br, struct net_bridge_port *port)
{
	struct hlist_node *n_store;
	struct br_cfm_mep *mep;

	ASSERT_RTNL();

	hlist_for_each_entry_safe(mep, n_store, &br->mep_list, head)
		if (mep->create.ifindex == port->dev->ifindex)
			mep_delete_implementation(br, mep);
}