Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 867 insertions, 0 deletions

diff --git a/net/bridge/br_cfm.c b/net/bridge/br_cfm.c
new file mode 100644
index 0000000000..a3c755d0a0
--- /dev/null
+++ b/net/bridge/br_cfm.c
@@ -0,0 +1,867 @@
+// 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;
+
+	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);
+}