xref: /openbmc/linux/net/bridge/br_cfm.c (revision 63705da3)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 
3 #include <linux/cfm_bridge.h>
4 #include <uapi/linux/cfm_bridge.h>
5 #include "br_private_cfm.h"
6 
7 static struct br_cfm_mep *br_mep_find(struct net_bridge *br, u32 instance)
8 {
9 	struct br_cfm_mep *mep;
10 
11 	hlist_for_each_entry(mep, &br->mep_list, head)
12 		if (mep->instance == instance)
13 			return mep;
14 
15 	return NULL;
16 }
17 
18 static struct br_cfm_mep *br_mep_find_ifindex(struct net_bridge *br,
19 					      u32 ifindex)
20 {
21 	struct br_cfm_mep *mep;
22 
23 	hlist_for_each_entry_rcu(mep, &br->mep_list, head,
24 				 lockdep_rtnl_is_held())
25 		if (mep->create.ifindex == ifindex)
26 			return mep;
27 
28 	return NULL;
29 }
30 
31 static struct br_cfm_peer_mep *br_peer_mep_find(struct br_cfm_mep *mep,
32 						u32 mepid)
33 {
34 	struct br_cfm_peer_mep *peer_mep;
35 
36 	hlist_for_each_entry_rcu(peer_mep, &mep->peer_mep_list, head,
37 				 lockdep_rtnl_is_held())
38 		if (peer_mep->mepid == mepid)
39 			return peer_mep;
40 
41 	return NULL;
42 }
43 
44 static struct net_bridge_port *br_mep_get_port(struct net_bridge *br,
45 					       u32 ifindex)
46 {
47 	struct net_bridge_port *port;
48 
49 	list_for_each_entry(port, &br->port_list, list)
50 		if (port->dev->ifindex == ifindex)
51 			return port;
52 
53 	return NULL;
54 }
55 
56 /* Calculate the CCM interval in us. */
57 static u32 interval_to_us(enum br_cfm_ccm_interval interval)
58 {
59 	switch (interval) {
60 	case BR_CFM_CCM_INTERVAL_NONE:
61 		return 0;
62 	case BR_CFM_CCM_INTERVAL_3_3_MS:
63 		return 3300;
64 	case BR_CFM_CCM_INTERVAL_10_MS:
65 		return 10 * 1000;
66 	case BR_CFM_CCM_INTERVAL_100_MS:
67 		return 100 * 1000;
68 	case BR_CFM_CCM_INTERVAL_1_SEC:
69 		return 1000 * 1000;
70 	case BR_CFM_CCM_INTERVAL_10_SEC:
71 		return 10 * 1000 * 1000;
72 	case BR_CFM_CCM_INTERVAL_1_MIN:
73 		return 60 * 1000 * 1000;
74 	case BR_CFM_CCM_INTERVAL_10_MIN:
75 		return 10 * 60 * 1000 * 1000;
76 	}
77 	return 0;
78 }
79 
80 /* Convert the interface interval to CCM PDU value. */
81 static u32 interval_to_pdu(enum br_cfm_ccm_interval interval)
82 {
83 	switch (interval) {
84 	case BR_CFM_CCM_INTERVAL_NONE:
85 		return 0;
86 	case BR_CFM_CCM_INTERVAL_3_3_MS:
87 		return 1;
88 	case BR_CFM_CCM_INTERVAL_10_MS:
89 		return 2;
90 	case BR_CFM_CCM_INTERVAL_100_MS:
91 		return 3;
92 	case BR_CFM_CCM_INTERVAL_1_SEC:
93 		return 4;
94 	case BR_CFM_CCM_INTERVAL_10_SEC:
95 		return 5;
96 	case BR_CFM_CCM_INTERVAL_1_MIN:
97 		return 6;
98 	case BR_CFM_CCM_INTERVAL_10_MIN:
99 		return 7;
100 	}
101 	return 0;
102 }
103 
104 /* Convert the CCM PDU value to interval on interface. */
105 static u32 pdu_to_interval(u32 value)
106 {
107 	switch (value) {
108 	case 0:
109 		return BR_CFM_CCM_INTERVAL_NONE;
110 	case 1:
111 		return BR_CFM_CCM_INTERVAL_3_3_MS;
112 	case 2:
113 		return BR_CFM_CCM_INTERVAL_10_MS;
114 	case 3:
115 		return BR_CFM_CCM_INTERVAL_100_MS;
116 	case 4:
117 		return BR_CFM_CCM_INTERVAL_1_SEC;
118 	case 5:
119 		return BR_CFM_CCM_INTERVAL_10_SEC;
120 	case 6:
121 		return BR_CFM_CCM_INTERVAL_1_MIN;
122 	case 7:
123 		return BR_CFM_CCM_INTERVAL_10_MIN;
124 	}
125 	return BR_CFM_CCM_INTERVAL_NONE;
126 }
127 
128 static void ccm_rx_timer_start(struct br_cfm_peer_mep *peer_mep)
129 {
130 	u32 interval_us;
131 
132 	interval_us = interval_to_us(peer_mep->mep->cc_config.exp_interval);
133 	/* Function ccm_rx_dwork must be called with 1/4
134 	 * of the configured CC 'expected_interval'
135 	 * in order to detect CCM defect after 3.25 interval.
136 	 */
137 	queue_delayed_work(system_wq, &peer_mep->ccm_rx_dwork,
138 			   usecs_to_jiffies(interval_us / 4));
139 }
140 
141 static void br_cfm_notify(int event, const struct net_bridge_port *port)
142 {
143 	u32 filter = RTEXT_FILTER_CFM_STATUS;
144 
145 	br_info_notify(event, port->br, NULL, filter);
146 }
147 
148 static void cc_peer_enable(struct br_cfm_peer_mep *peer_mep)
149 {
150 	memset(&peer_mep->cc_status, 0, sizeof(peer_mep->cc_status));
151 	peer_mep->ccm_rx_count_miss = 0;
152 
153 	ccm_rx_timer_start(peer_mep);
154 }
155 
156 static void cc_peer_disable(struct br_cfm_peer_mep *peer_mep)
157 {
158 	cancel_delayed_work_sync(&peer_mep->ccm_rx_dwork);
159 }
160 
161 static struct sk_buff *ccm_frame_build(struct br_cfm_mep *mep,
162 				       const struct br_cfm_cc_ccm_tx_info *const tx_info)
163 
164 {
165 	struct br_cfm_common_hdr *common_hdr;
166 	struct net_bridge_port *b_port;
167 	struct br_cfm_maid *maid;
168 	u8 *itu_reserved, *e_tlv;
169 	struct ethhdr *eth_hdr;
170 	struct sk_buff *skb;
171 	__be32 *status_tlv;
172 	__be32 *snumber;
173 	__be16 *mepid;
174 
175 	skb = dev_alloc_skb(CFM_CCM_MAX_FRAME_LENGTH);
176 	if (!skb)
177 		return NULL;
178 
179 	rcu_read_lock();
180 	b_port = rcu_dereference(mep->b_port);
181 	if (!b_port) {
182 		kfree_skb(skb);
183 		rcu_read_unlock();
184 		return NULL;
185 	}
186 	skb->dev = b_port->dev;
187 	rcu_read_unlock();
188 	/* The device cannot be deleted until the work_queue functions has
189 	 * completed. This function is called from ccm_tx_work_expired()
190 	 * that is a work_queue functions.
191 	 */
192 
193 	skb->protocol = htons(ETH_P_CFM);
194 	skb->priority = CFM_FRAME_PRIO;
195 
196 	/* Ethernet header */
197 	eth_hdr = skb_put(skb, sizeof(*eth_hdr));
198 	ether_addr_copy(eth_hdr->h_dest, tx_info->dmac.addr);
199 	ether_addr_copy(eth_hdr->h_source, mep->config.unicast_mac.addr);
200 	eth_hdr->h_proto = htons(ETH_P_CFM);
201 
202 	/* Common CFM Header */
203 	common_hdr = skb_put(skb, sizeof(*common_hdr));
204 	common_hdr->mdlevel_version = mep->config.mdlevel << 5;
205 	common_hdr->opcode = BR_CFM_OPCODE_CCM;
206 	common_hdr->flags = (mep->rdi << 7) |
207 			    interval_to_pdu(mep->cc_config.exp_interval);
208 	common_hdr->tlv_offset = CFM_CCM_TLV_OFFSET;
209 
210 	/* Sequence number */
211 	snumber = skb_put(skb, sizeof(*snumber));
212 	if (tx_info->seq_no_update) {
213 		*snumber = cpu_to_be32(mep->ccm_tx_snumber);
214 		mep->ccm_tx_snumber += 1;
215 	} else {
216 		*snumber = 0;
217 	}
218 
219 	mepid = skb_put(skb, sizeof(*mepid));
220 	*mepid = cpu_to_be16((u16)mep->config.mepid);
221 
222 	maid = skb_put(skb, sizeof(*maid));
223 	memcpy(maid->data, mep->cc_config.exp_maid.data, sizeof(maid->data));
224 
225 	/* ITU reserved (CFM_CCM_ITU_RESERVED_SIZE octets) */
226 	itu_reserved = skb_put(skb, CFM_CCM_ITU_RESERVED_SIZE);
227 	memset(itu_reserved, 0, CFM_CCM_ITU_RESERVED_SIZE);
228 
229 	/* Generel CFM TLV format:
230 	 * TLV type:		one byte
231 	 * TLV value length:	two bytes
232 	 * TLV value:		'TLV value length' bytes
233 	 */
234 
235 	/* Port status TLV. The value length is 1. Total of 4 bytes. */
236 	if (tx_info->port_tlv) {
237 		status_tlv = skb_put(skb, sizeof(*status_tlv));
238 		*status_tlv = cpu_to_be32((CFM_PORT_STATUS_TLV_TYPE << 24) |
239 					  (1 << 8) |	/* Value length */
240 					  (tx_info->port_tlv_value & 0xFF));
241 	}
242 
243 	/* Interface status TLV. The value length is 1. Total of 4 bytes. */
244 	if (tx_info->if_tlv) {
245 		status_tlv = skb_put(skb, sizeof(*status_tlv));
246 		*status_tlv = cpu_to_be32((CFM_IF_STATUS_TLV_TYPE << 24) |
247 					  (1 << 8) |	/* Value length */
248 					  (tx_info->if_tlv_value & 0xFF));
249 	}
250 
251 	/* End TLV */
252 	e_tlv = skb_put(skb, sizeof(*e_tlv));
253 	*e_tlv = CFM_ENDE_TLV_TYPE;
254 
255 	return skb;
256 }
257 
258 static void ccm_frame_tx(struct sk_buff *skb)
259 {
260 	skb_reset_network_header(skb);
261 	dev_queue_xmit(skb);
262 }
263 
264 /* This function is called with the configured CC 'expected_interval'
265  * in order to drive CCM transmission when enabled.
266  */
267 static void ccm_tx_work_expired(struct work_struct *work)
268 {
269 	struct delayed_work *del_work;
270 	struct br_cfm_mep *mep;
271 	struct sk_buff *skb;
272 	u32 interval_us;
273 
274 	del_work = to_delayed_work(work);
275 	mep = container_of(del_work, struct br_cfm_mep, ccm_tx_dwork);
276 
277 	if (time_before_eq(mep->ccm_tx_end, jiffies)) {
278 		/* Transmission period has ended */
279 		mep->cc_ccm_tx_info.period = 0;
280 		return;
281 	}
282 
283 	skb = ccm_frame_build(mep, &mep->cc_ccm_tx_info);
284 	if (skb)
285 		ccm_frame_tx(skb);
286 
287 	interval_us = interval_to_us(mep->cc_config.exp_interval);
288 	queue_delayed_work(system_wq, &mep->ccm_tx_dwork,
289 			   usecs_to_jiffies(interval_us));
290 }
291 
292 /* This function is called with 1/4 of the configured CC 'expected_interval'
293  * in order to detect CCM defect after 3.25 interval.
294  */
295 static void ccm_rx_work_expired(struct work_struct *work)
296 {
297 	struct br_cfm_peer_mep *peer_mep;
298 	struct net_bridge_port *b_port;
299 	struct delayed_work *del_work;
300 
301 	del_work = to_delayed_work(work);
302 	peer_mep = container_of(del_work, struct br_cfm_peer_mep, ccm_rx_dwork);
303 
304 	/* After 13 counts (4 * 3,25) then 3.25 intervals are expired */
305 	if (peer_mep->ccm_rx_count_miss < 13) {
306 		/* 3.25 intervals are NOT expired without CCM reception */
307 		peer_mep->ccm_rx_count_miss++;
308 
309 		/* Start timer again */
310 		ccm_rx_timer_start(peer_mep);
311 	} else {
312 		/* 3.25 intervals are expired without CCM reception.
313 		 * CCM defect detected
314 		 */
315 		peer_mep->cc_status.ccm_defect = true;
316 
317 		/* Change in CCM defect status - notify */
318 		rcu_read_lock();
319 		b_port = rcu_dereference(peer_mep->mep->b_port);
320 		if (b_port)
321 			br_cfm_notify(RTM_NEWLINK, b_port);
322 		rcu_read_unlock();
323 	}
324 }
325 
326 static u32 ccm_tlv_extract(struct sk_buff *skb, u32 index,
327 			   struct br_cfm_peer_mep *peer_mep)
328 {
329 	__be32 *s_tlv;
330 	__be32 _s_tlv;
331 	u32 h_s_tlv;
332 	u8 *e_tlv;
333 	u8 _e_tlv;
334 
335 	e_tlv = skb_header_pointer(skb, index, sizeof(_e_tlv), &_e_tlv);
336 	if (!e_tlv)
337 		return 0;
338 
339 	/* TLV is present - get the status TLV */
340 	s_tlv = skb_header_pointer(skb,
341 				   index,
342 				   sizeof(_s_tlv), &_s_tlv);
343 	if (!s_tlv)
344 		return 0;
345 
346 	h_s_tlv = ntohl(*s_tlv);
347 	if ((h_s_tlv >> 24) == CFM_IF_STATUS_TLV_TYPE) {
348 		/* Interface status TLV */
349 		peer_mep->cc_status.tlv_seen = true;
350 		peer_mep->cc_status.if_tlv_value = (h_s_tlv & 0xFF);
351 	}
352 
353 	if ((h_s_tlv >> 24) == CFM_PORT_STATUS_TLV_TYPE) {
354 		/* Port status TLV */
355 		peer_mep->cc_status.tlv_seen = true;
356 		peer_mep->cc_status.port_tlv_value = (h_s_tlv & 0xFF);
357 	}
358 
359 	/* The Sender ID TLV is not handled */
360 	/* The Organization-Specific TLV is not handled */
361 
362 	/* Return the length of this tlv.
363 	 * This is the length of the value field plus 3 bytes for size of type
364 	 * field and length field
365 	 */
366 	return ((h_s_tlv >> 8) & 0xFFFF) + 3;
367 }
368 
369 /* note: already called with rcu_read_lock */
370 static int br_cfm_frame_rx(struct net_bridge_port *port, struct sk_buff *skb)
371 {
372 	u32 mdlevel, interval, size, index, max;
373 	const struct br_cfm_common_hdr *hdr;
374 	struct br_cfm_peer_mep *peer_mep;
375 	const struct br_cfm_maid *maid;
376 	struct br_cfm_common_hdr _hdr;
377 	struct br_cfm_maid _maid;
378 	struct br_cfm_mep *mep;
379 	struct net_bridge *br;
380 	__be32 *snumber;
381 	__be32 _snumber;
382 	__be16 *mepid;
383 	__be16 _mepid;
384 
385 	if (port->state == BR_STATE_DISABLED)
386 		return 0;
387 
388 	hdr = skb_header_pointer(skb, 0, sizeof(_hdr), &_hdr);
389 	if (!hdr)
390 		return 1;
391 
392 	br = port->br;
393 	mep = br_mep_find_ifindex(br, port->dev->ifindex);
394 	if (unlikely(!mep))
395 		/* No MEP on this port - must be forwarded */
396 		return 0;
397 
398 	mdlevel = hdr->mdlevel_version >> 5;
399 	if (mdlevel > mep->config.mdlevel)
400 		/* The level is above this MEP level - must be forwarded */
401 		return 0;
402 
403 	if ((hdr->mdlevel_version & 0x1F) != 0) {
404 		/* Invalid version */
405 		mep->status.version_unexp_seen = true;
406 		return 1;
407 	}
408 
409 	if (mdlevel < mep->config.mdlevel) {
410 		/* The level is below this MEP level */
411 		mep->status.rx_level_low_seen = true;
412 		return 1;
413 	}
414 
415 	if (hdr->opcode == BR_CFM_OPCODE_CCM) {
416 		/* CCM PDU received. */
417 		/* MA ID is after common header + sequence number + MEP ID */
418 		maid = skb_header_pointer(skb,
419 					  CFM_CCM_PDU_MAID_OFFSET,
420 					  sizeof(_maid), &_maid);
421 		if (!maid)
422 			return 1;
423 		if (memcmp(maid->data, mep->cc_config.exp_maid.data,
424 			   sizeof(maid->data)))
425 			/* MA ID not as expected */
426 			return 1;
427 
428 		/* MEP ID is after common header + sequence number */
429 		mepid = skb_header_pointer(skb,
430 					   CFM_CCM_PDU_MEPID_OFFSET,
431 					   sizeof(_mepid), &_mepid);
432 		if (!mepid)
433 			return 1;
434 		peer_mep = br_peer_mep_find(mep, (u32)ntohs(*mepid));
435 		if (!peer_mep)
436 			return 1;
437 
438 		/* Interval is in common header flags */
439 		interval = hdr->flags & 0x07;
440 		if (mep->cc_config.exp_interval != pdu_to_interval(interval))
441 			/* Interval not as expected */
442 			return 1;
443 
444 		/* A valid CCM frame is received */
445 		if (peer_mep->cc_status.ccm_defect) {
446 			peer_mep->cc_status.ccm_defect = false;
447 
448 			/* Change in CCM defect status - notify */
449 			br_cfm_notify(RTM_NEWLINK, port);
450 
451 			/* Start CCM RX timer */
452 			ccm_rx_timer_start(peer_mep);
453 		}
454 
455 		peer_mep->cc_status.seen = true;
456 		peer_mep->ccm_rx_count_miss = 0;
457 
458 		/* RDI is in common header flags */
459 		peer_mep->cc_status.rdi = (hdr->flags & 0x80) ? true : false;
460 
461 		/* Sequence number is after common header */
462 		snumber = skb_header_pointer(skb,
463 					     CFM_CCM_PDU_SEQNR_OFFSET,
464 					     sizeof(_snumber), &_snumber);
465 		if (!snumber)
466 			return 1;
467 		if (ntohl(*snumber) != (mep->ccm_rx_snumber + 1))
468 			/* Unexpected sequence number */
469 			peer_mep->cc_status.seq_unexp_seen = true;
470 
471 		mep->ccm_rx_snumber = ntohl(*snumber);
472 
473 		/* TLV end is after common header + sequence number + MEP ID +
474 		 * MA ID + ITU reserved
475 		 */
476 		index = CFM_CCM_PDU_TLV_OFFSET;
477 		max = 0;
478 		do { /* Handle all TLVs */
479 			size = ccm_tlv_extract(skb, index, peer_mep);
480 			index += size;
481 			max += 1;
482 		} while (size != 0 && max < 4); /* Max four TLVs possible */
483 
484 		return 1;
485 	}
486 
487 	mep->status.opcode_unexp_seen = true;
488 
489 	return 1;
490 }
491 
492 static struct br_frame_type cfm_frame_type __read_mostly = {
493 	.type = cpu_to_be16(ETH_P_CFM),
494 	.frame_handler = br_cfm_frame_rx,
495 };
496 
497 int br_cfm_mep_create(struct net_bridge *br,
498 		      const u32 instance,
499 		      struct br_cfm_mep_create *const create,
500 		      struct netlink_ext_ack *extack)
501 {
502 	struct net_bridge_port *p;
503 	struct br_cfm_mep *mep;
504 
505 	ASSERT_RTNL();
506 
507 	if (create->domain == BR_CFM_VLAN) {
508 		NL_SET_ERR_MSG_MOD(extack,
509 				   "VLAN domain not supported");
510 		return -EINVAL;
511 	}
512 	if (create->domain != BR_CFM_PORT) {
513 		NL_SET_ERR_MSG_MOD(extack,
514 				   "Invalid domain value");
515 		return -EINVAL;
516 	}
517 	if (create->direction == BR_CFM_MEP_DIRECTION_UP) {
518 		NL_SET_ERR_MSG_MOD(extack,
519 				   "Up-MEP not supported");
520 		return -EINVAL;
521 	}
522 	if (create->direction != BR_CFM_MEP_DIRECTION_DOWN) {
523 		NL_SET_ERR_MSG_MOD(extack,
524 				   "Invalid direction value");
525 		return -EINVAL;
526 	}
527 	p = br_mep_get_port(br, create->ifindex);
528 	if (!p) {
529 		NL_SET_ERR_MSG_MOD(extack,
530 				   "Port is not related to bridge");
531 		return -EINVAL;
532 	}
533 	mep = br_mep_find(br, instance);
534 	if (mep) {
535 		NL_SET_ERR_MSG_MOD(extack,
536 				   "MEP instance already exists");
537 		return -EEXIST;
538 	}
539 
540 	/* In PORT domain only one instance can be created per port */
541 	if (create->domain == BR_CFM_PORT) {
542 		mep = br_mep_find_ifindex(br, create->ifindex);
543 		if (mep) {
544 			NL_SET_ERR_MSG_MOD(extack,
545 					   "Only one Port MEP on a port allowed");
546 			return -EINVAL;
547 		}
548 	}
549 
550 	mep = kzalloc(sizeof(*mep), GFP_KERNEL);
551 	if (!mep)
552 		return -ENOMEM;
553 
554 	mep->create = *create;
555 	mep->instance = instance;
556 	rcu_assign_pointer(mep->b_port, p);
557 
558 	INIT_HLIST_HEAD(&mep->peer_mep_list);
559 	INIT_DELAYED_WORK(&mep->ccm_tx_dwork, ccm_tx_work_expired);
560 
561 	if (hlist_empty(&br->mep_list))
562 		br_add_frame(br, &cfm_frame_type);
563 
564 	hlist_add_tail_rcu(&mep->head, &br->mep_list);
565 
566 	return 0;
567 }
568 
569 static void mep_delete_implementation(struct net_bridge *br,
570 				      struct br_cfm_mep *mep)
571 {
572 	struct br_cfm_peer_mep *peer_mep;
573 	struct hlist_node *n_store;
574 
575 	ASSERT_RTNL();
576 
577 	/* Empty and free peer MEP list */
578 	hlist_for_each_entry_safe(peer_mep, n_store, &mep->peer_mep_list, head) {
579 		cancel_delayed_work_sync(&peer_mep->ccm_rx_dwork);
580 		hlist_del_rcu(&peer_mep->head);
581 		kfree_rcu(peer_mep, rcu);
582 	}
583 
584 	cancel_delayed_work_sync(&mep->ccm_tx_dwork);
585 
586 	RCU_INIT_POINTER(mep->b_port, NULL);
587 	hlist_del_rcu(&mep->head);
588 	kfree_rcu(mep, rcu);
589 
590 	if (hlist_empty(&br->mep_list))
591 		br_del_frame(br, &cfm_frame_type);
592 }
593 
594 int br_cfm_mep_delete(struct net_bridge *br,
595 		      const u32 instance,
596 		      struct netlink_ext_ack *extack)
597 {
598 	struct br_cfm_mep *mep;
599 
600 	ASSERT_RTNL();
601 
602 	mep = br_mep_find(br, instance);
603 	if (!mep) {
604 		NL_SET_ERR_MSG_MOD(extack,
605 				   "MEP instance does not exists");
606 		return -ENOENT;
607 	}
608 
609 	mep_delete_implementation(br, mep);
610 
611 	return 0;
612 }
613 
614 int br_cfm_mep_config_set(struct net_bridge *br,
615 			  const u32 instance,
616 			  const struct br_cfm_mep_config *const config,
617 			  struct netlink_ext_ack *extack)
618 {
619 	struct br_cfm_mep *mep;
620 
621 	ASSERT_RTNL();
622 
623 	mep = br_mep_find(br, instance);
624 	if (!mep) {
625 		NL_SET_ERR_MSG_MOD(extack,
626 				   "MEP instance does not exists");
627 		return -ENOENT;
628 	}
629 
630 	mep->config = *config;
631 
632 	return 0;
633 }
634 
635 int br_cfm_cc_config_set(struct net_bridge *br,
636 			 const u32 instance,
637 			 const struct br_cfm_cc_config *const config,
638 			 struct netlink_ext_ack *extack)
639 {
640 	struct br_cfm_peer_mep *peer_mep;
641 	struct br_cfm_mep *mep;
642 
643 	ASSERT_RTNL();
644 
645 	mep = br_mep_find(br, instance);
646 	if (!mep) {
647 		NL_SET_ERR_MSG_MOD(extack,
648 				   "MEP instance does not exists");
649 		return -ENOENT;
650 	}
651 
652 	/* Check for no change in configuration */
653 	if (memcmp(config, &mep->cc_config, sizeof(*config)) == 0)
654 		return 0;
655 
656 	if (config->enable && !mep->cc_config.enable)
657 		/* CC is enabled */
658 		hlist_for_each_entry(peer_mep, &mep->peer_mep_list, head)
659 			cc_peer_enable(peer_mep);
660 
661 	if (!config->enable && mep->cc_config.enable)
662 		/* CC is disabled */
663 		hlist_for_each_entry(peer_mep, &mep->peer_mep_list, head)
664 			cc_peer_disable(peer_mep);
665 
666 	mep->cc_config = *config;
667 	mep->ccm_rx_snumber = 0;
668 	mep->ccm_tx_snumber = 1;
669 
670 	return 0;
671 }
672 
673 int br_cfm_cc_peer_mep_add(struct net_bridge *br, const u32 instance,
674 			   u32 mepid,
675 			   struct netlink_ext_ack *extack)
676 {
677 	struct br_cfm_peer_mep *peer_mep;
678 	struct br_cfm_mep *mep;
679 
680 	ASSERT_RTNL();
681 
682 	mep = br_mep_find(br, instance);
683 	if (!mep) {
684 		NL_SET_ERR_MSG_MOD(extack,
685 				   "MEP instance does not exists");
686 		return -ENOENT;
687 	}
688 
689 	peer_mep = br_peer_mep_find(mep, mepid);
690 	if (peer_mep) {
691 		NL_SET_ERR_MSG_MOD(extack,
692 				   "Peer MEP-ID already exists");
693 		return -EEXIST;
694 	}
695 
696 	peer_mep = kzalloc(sizeof(*peer_mep), GFP_KERNEL);
697 	if (!peer_mep)
698 		return -ENOMEM;
699 
700 	peer_mep->mepid = mepid;
701 	peer_mep->mep = mep;
702 	INIT_DELAYED_WORK(&peer_mep->ccm_rx_dwork, ccm_rx_work_expired);
703 
704 	if (mep->cc_config.enable)
705 		cc_peer_enable(peer_mep);
706 
707 	hlist_add_tail_rcu(&peer_mep->head, &mep->peer_mep_list);
708 
709 	return 0;
710 }
711 
712 int br_cfm_cc_peer_mep_remove(struct net_bridge *br, const u32 instance,
713 			      u32 mepid,
714 			      struct netlink_ext_ack *extack)
715 {
716 	struct br_cfm_peer_mep *peer_mep;
717 	struct br_cfm_mep *mep;
718 
719 	ASSERT_RTNL();
720 
721 	mep = br_mep_find(br, instance);
722 	if (!mep) {
723 		NL_SET_ERR_MSG_MOD(extack,
724 				   "MEP instance does not exists");
725 		return -ENOENT;
726 	}
727 
728 	peer_mep = br_peer_mep_find(mep, mepid);
729 	if (!peer_mep) {
730 		NL_SET_ERR_MSG_MOD(extack,
731 				   "Peer MEP-ID does not exists");
732 		return -ENOENT;
733 	}
734 
735 	cc_peer_disable(peer_mep);
736 
737 	hlist_del_rcu(&peer_mep->head);
738 	kfree_rcu(peer_mep, rcu);
739 
740 	return 0;
741 }
742 
743 int br_cfm_cc_rdi_set(struct net_bridge *br, const u32 instance,
744 		      const bool rdi, struct netlink_ext_ack *extack)
745 {
746 	struct br_cfm_mep *mep;
747 
748 	ASSERT_RTNL();
749 
750 	mep = br_mep_find(br, instance);
751 	if (!mep) {
752 		NL_SET_ERR_MSG_MOD(extack,
753 				   "MEP instance does not exists");
754 		return -ENOENT;
755 	}
756 
757 	mep->rdi = rdi;
758 
759 	return 0;
760 }
761 
762 int br_cfm_cc_ccm_tx(struct net_bridge *br, const u32 instance,
763 		     const struct br_cfm_cc_ccm_tx_info *const tx_info,
764 		     struct netlink_ext_ack *extack)
765 {
766 	struct br_cfm_mep *mep;
767 
768 	ASSERT_RTNL();
769 
770 	mep = br_mep_find(br, instance);
771 	if (!mep) {
772 		NL_SET_ERR_MSG_MOD(extack,
773 				   "MEP instance does not exists");
774 		return -ENOENT;
775 	}
776 
777 	if (memcmp(tx_info, &mep->cc_ccm_tx_info, sizeof(*tx_info)) == 0) {
778 		/* No change in tx_info. */
779 		if (mep->cc_ccm_tx_info.period == 0)
780 			/* Transmission is not enabled - just return */
781 			return 0;
782 
783 		/* Transmission is ongoing, the end time is recalculated */
784 		mep->ccm_tx_end = jiffies +
785 				  usecs_to_jiffies(tx_info->period * 1000000);
786 		return 0;
787 	}
788 
789 	if (tx_info->period == 0 && mep->cc_ccm_tx_info.period == 0)
790 		/* Some change in info and transmission is not ongoing */
791 		goto save;
792 
793 	if (tx_info->period != 0 && mep->cc_ccm_tx_info.period != 0) {
794 		/* Some change in info and transmission is ongoing
795 		 * The end time is recalculated
796 		 */
797 		mep->ccm_tx_end = jiffies +
798 				  usecs_to_jiffies(tx_info->period * 1000000);
799 
800 		goto save;
801 	}
802 
803 	if (tx_info->period == 0 && mep->cc_ccm_tx_info.period != 0) {
804 		cancel_delayed_work_sync(&mep->ccm_tx_dwork);
805 		goto save;
806 	}
807 
808 	/* Start delayed work to transmit CCM frames. It is done with zero delay
809 	 * to send first frame immediately
810 	 */
811 	mep->ccm_tx_end = jiffies + usecs_to_jiffies(tx_info->period * 1000000);
812 	queue_delayed_work(system_wq, &mep->ccm_tx_dwork, 0);
813 
814 save:
815 	mep->cc_ccm_tx_info = *tx_info;
816 
817 	return 0;
818 }
819 
820 int br_cfm_mep_count(struct net_bridge *br, u32 *count)
821 {
822 	struct br_cfm_mep *mep;
823 
824 	*count = 0;
825 
826 	rcu_read_lock();
827 	hlist_for_each_entry_rcu(mep, &br->mep_list, head)
828 		*count += 1;
829 	rcu_read_unlock();
830 
831 	return 0;
832 }
833 
834 int br_cfm_peer_mep_count(struct net_bridge *br, u32 *count)
835 {
836 	struct br_cfm_peer_mep *peer_mep;
837 	struct br_cfm_mep *mep;
838 
839 	*count = 0;
840 
841 	rcu_read_lock();
842 	hlist_for_each_entry_rcu(mep, &br->mep_list, head)
843 		hlist_for_each_entry_rcu(peer_mep, &mep->peer_mep_list, head)
844 			*count += 1;
845 	rcu_read_unlock();
846 
847 	return 0;
848 }
849 
850 bool br_cfm_created(struct net_bridge *br)
851 {
852 	return !hlist_empty(&br->mep_list);
853 }
854 
855 /* Deletes the CFM instances on a specific bridge port
856  */
857 void br_cfm_port_del(struct net_bridge *br, struct net_bridge_port *port)
858 {
859 	struct hlist_node *n_store;
860 	struct br_cfm_mep *mep;
861 
862 	ASSERT_RTNL();
863 
864 	hlist_for_each_entry_safe(mep, n_store, &br->mep_list, head)
865 		if (mep->create.ifindex == port->dev->ifindex)
866 			mep_delete_implementation(br, mep);
867 }
868