Merge branch 'net-bridge-cfm-add-support-for-connectivity-fault-management-cfm'

Henrik Bjoernlund says:

====================
net: bridge: cfm: Add support for Connectivity Fault Management(CFM)

Connectivity Fault Management (CFM) is defined in 802.1Q
section 12.14.

Connectivity Fault Management (CFM) comprises capabilities for
detecting, verifying, and isolating connectivity failures in Virtual
Bridged Networks. These capabilities can be used in networks
operated by multiple independent organizations, each with restricted
management access to each other’s equipment.

CFM functions are partitioned as follows:
    — Path discovery
    — Fault detection
    — Fault verification and isolation
    — Fault notification
    — Fault recovery

The primary CFM protocol shims are called Maintenance Points (MPs).
A MP can be either a MEP or a MHF.
The MEP:
    -It is the Maintenance association End Point
     described in 802.1Q section 19.2.
    -It is created on a specific level (1-7) and is assuring
     that no CFM frames are passing through this MEP on lower levels.
    -It initiates and terminates/validates CFM frames on its level.
    -It can only exist on a port that is related to a bridge.
The MHF:
    -It is the Maintenance Domain Intermediate Point
     (MIP) Half Function (MHF) described in 802.1Q section 19.3.
    -It is created on a specific level (1-7).
    -It is extracting/injecting certain CFM frame on this level.
    -It can only exist on a port that is related to a bridge.
    -Currently not supported.

There are defined the following CFM protocol functions:
    -Continuity Check
    -Loopback. Currently not supported.
    -Linktrace. Currently not supported.

This CFM component supports create/delete of MEP instances and
configuration of the different CFM protocols. Also status information
can be fetched and delivered through notification due to defect
status change.

The user interacts with CFM using the 'cfm' user space client
program, the client talks with the kernel using netlink.

Any notification emitted by CFM from the kernel can be monitored in
user space by starting 'cfm_server' program.

Currently this 'cfm' and 'cfm_server' programs are standalone placed
in a cfm repository https://github.com/microchip-ung/cfm but it is
considered to integrate this into 'iproute2'.

v1 -> v2
    Added the CFM switchdev interface and also added utilization by
    calling the interface from the kernel CFM implementation trying
    to offload CFM functionality to HW. This offload (CFM driver) is
    currently not implemented.

    Corrections based on RCF comments:
        -The single CFM kernel implementation Patch is broken up into
         three patches.
        -Changed the list of MEP instances from list_head to
         hlist_head.
        -Removed unnecessary RCU list traversing.
        -Solved RCU unlocking problem.
        -Removed unnecessary comments.
        -Added ASSERT_RTNL() where required.
        -Shaping up on error messages.
        -Correction NETLINK br_fill_ifinfo() to be able to handle
         'filter_mask' with multiple flags asserted.

v2 -> v3
    -The switchdev definition and utilization has been removed as
     there was no switchdev implementation.
    -Some compiling issues are fixed as Reported-by:
     kernel test robot <lkp@intel.com>.

v3 -> v4
    -Fixed potential crash during hlist walk where elements are
     removed.
    -Giving all commits unique titles.
    -NETLINK implementation split into three commits.
    -Commit "bridge: cfm: Bridge port remove" is merged with
     commit "bridge: cfm: Kernel space implementation of CFM. MEP
     create/delete."

v4 -> v5
    -Reordered members in struct net_bridge to bring member
     frame_type_list to the first cache line.
    -Helper functions nla_get_mac() and nla_get_maid() are removed.
    -The NLA_POLICY_NESTED() macro is used to initialize the
     br_cfm_policy array.
    -Fixed reverse xmas tree.

v5 -> v6
    -Fixed that the SKB buffer was not freed during error handling return.
    -Removed unused struct definition.
    -Changed bool to u8 bitfields for space save.
    -Utilizing the NETLINK policy validation feature.

v6 -> v7
    -Removed check of parameters in br_cfm_mep_config_set() and
     br_cfm_cc_peer_mep_add() in first commit of MEP implementation
     (Patch 4 out of 10)
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: Henrik Bjoernlund <henrik.bjoernlund@microchip.com>
====================

Link: https://lore.kernel.org/r/20201027100251.3241719-1-henrik.bjoernlund@microchip.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

include/uapi/linux/cfm_bridge.h

+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+
+#ifndef _UAPI_LINUX_CFM_BRIDGE_H_
+#define _UAPI_LINUX_CFM_BRIDGE_H_
+
+#include <linux/types.h>
+#include <linux/if_ether.h>
+
+#define ETHER_HEADER_LENGTH		(6+6+4+2)
+#define CFM_MAID_LENGTH			48
+#define CFM_CCM_PDU_LENGTH		75
+#define CFM_PORT_STATUS_TLV_LENGTH	4
+#define CFM_IF_STATUS_TLV_LENGTH	4
+#define CFM_IF_STATUS_TLV_TYPE		4
+#define CFM_PORT_STATUS_TLV_TYPE	2
+#define CFM_ENDE_TLV_TYPE		0
+#define CFM_CCM_MAX_FRAME_LENGTH	(ETHER_HEADER_LENGTH+\
+					 CFM_CCM_PDU_LENGTH+\
+					 CFM_PORT_STATUS_TLV_LENGTH+\
+					 CFM_IF_STATUS_TLV_LENGTH)
+#define CFM_FRAME_PRIO			7
+#define CFM_CCM_TLV_OFFSET		70
+#define CFM_CCM_PDU_MAID_OFFSET		10
+#define CFM_CCM_PDU_MEPID_OFFSET	8
+#define CFM_CCM_PDU_SEQNR_OFFSET	4
+#define CFM_CCM_PDU_TLV_OFFSET		74
+#define CFM_CCM_ITU_RESERVED_SIZE	16
+
+struct br_cfm_common_hdr {
+	__u8 mdlevel_version;
+	__u8 opcode;
+	__u8 flags;
+	__u8 tlv_offset;
+};
+
+enum br_cfm_opcodes {
+	BR_CFM_OPCODE_CCM = 0x1,
+};
+
+/* MEP domain */
+enum br_cfm_domain {
+	BR_CFM_PORT,
+	BR_CFM_VLAN,
+};
+
+/* MEP direction */
+enum br_cfm_mep_direction {
+	BR_CFM_MEP_DIRECTION_DOWN,
+	BR_CFM_MEP_DIRECTION_UP,
+};
+
+/* CCM interval supported. */
+enum br_cfm_ccm_interval {
+	BR_CFM_CCM_INTERVAL_NONE,
+	BR_CFM_CCM_INTERVAL_3_3_MS,
+	BR_CFM_CCM_INTERVAL_10_MS,
+	BR_CFM_CCM_INTERVAL_100_MS,
+	BR_CFM_CCM_INTERVAL_1_SEC,
+	BR_CFM_CCM_INTERVAL_10_SEC,
+	BR_CFM_CCM_INTERVAL_1_MIN,
+	BR_CFM_CCM_INTERVAL_10_MIN,
+};
+
+#endif

include/uapi/linux/if_bridge.h

@@ -121,6 +121,7 @@ enum {
 	IFLA_BRIDGE_VLAN_INFO,
 	IFLA_BRIDGE_VLAN_TUNNEL_INFO,
 	IFLA_BRIDGE_MRP,
+	IFLA_BRIDGE_CFM,
 	__IFLA_BRIDGE_MAX,
 };
 #define IFLA_BRIDGE_MAX (__IFLA_BRIDGE_MAX - 1)
@@ -328,6 +329,130 @@ struct br_mrp_start_in_test {
 	__u16 in_id;
 };
 
+enum {
+	IFLA_BRIDGE_CFM_UNSPEC,
+	IFLA_BRIDGE_CFM_MEP_CREATE,
+	IFLA_BRIDGE_CFM_MEP_DELETE,
+	IFLA_BRIDGE_CFM_MEP_CONFIG,
+	IFLA_BRIDGE_CFM_CC_CONFIG,
+	IFLA_BRIDGE_CFM_CC_PEER_MEP_ADD,
+	IFLA_BRIDGE_CFM_CC_PEER_MEP_REMOVE,
+	IFLA_BRIDGE_CFM_CC_RDI,
+	IFLA_BRIDGE_CFM_CC_CCM_TX,
+	IFLA_BRIDGE_CFM_MEP_CREATE_INFO,
+	IFLA_BRIDGE_CFM_MEP_CONFIG_INFO,
+	IFLA_BRIDGE_CFM_CC_CONFIG_INFO,
+	IFLA_BRIDGE_CFM_CC_RDI_INFO,
+	IFLA_BRIDGE_CFM_CC_CCM_TX_INFO,
+	IFLA_BRIDGE_CFM_CC_PEER_MEP_INFO,
+	IFLA_BRIDGE_CFM_MEP_STATUS_INFO,
+	IFLA_BRIDGE_CFM_CC_PEER_STATUS_INFO,
+	__IFLA_BRIDGE_CFM_MAX,
+};
+
+#define IFLA_BRIDGE_CFM_MAX (__IFLA_BRIDGE_CFM_MAX - 1)
+
+enum {
+	IFLA_BRIDGE_CFM_MEP_CREATE_UNSPEC,
+	IFLA_BRIDGE_CFM_MEP_CREATE_INSTANCE,
+	IFLA_BRIDGE_CFM_MEP_CREATE_DOMAIN,
+	IFLA_BRIDGE_CFM_MEP_CREATE_DIRECTION,
+	IFLA_BRIDGE_CFM_MEP_CREATE_IFINDEX,
+	__IFLA_BRIDGE_CFM_MEP_CREATE_MAX,
+};
+
+#define IFLA_BRIDGE_CFM_MEP_CREATE_MAX (__IFLA_BRIDGE_CFM_MEP_CREATE_MAX - 1)
+
+enum {
+	IFLA_BRIDGE_CFM_MEP_DELETE_UNSPEC,
+	IFLA_BRIDGE_CFM_MEP_DELETE_INSTANCE,
+	__IFLA_BRIDGE_CFM_MEP_DELETE_MAX,
+};
+
+#define IFLA_BRIDGE_CFM_MEP_DELETE_MAX (__IFLA_BRIDGE_CFM_MEP_DELETE_MAX - 1)
+
+enum {
+	IFLA_BRIDGE_CFM_MEP_CONFIG_UNSPEC,
+	IFLA_BRIDGE_CFM_MEP_CONFIG_INSTANCE,
+	IFLA_BRIDGE_CFM_MEP_CONFIG_UNICAST_MAC,
+	IFLA_BRIDGE_CFM_MEP_CONFIG_MDLEVEL,
+	IFLA_BRIDGE_CFM_MEP_CONFIG_MEPID,
+	__IFLA_BRIDGE_CFM_MEP_CONFIG_MAX,
+};
+
+#define IFLA_BRIDGE_CFM_MEP_CONFIG_MAX (__IFLA_BRIDGE_CFM_MEP_CONFIG_MAX - 1)
+
+enum {
+	IFLA_BRIDGE_CFM_CC_CONFIG_UNSPEC,
+	IFLA_BRIDGE_CFM_CC_CONFIG_INSTANCE,
+	IFLA_BRIDGE_CFM_CC_CONFIG_ENABLE,
+	IFLA_BRIDGE_CFM_CC_CONFIG_EXP_INTERVAL,
+	IFLA_BRIDGE_CFM_CC_CONFIG_EXP_MAID,
+	__IFLA_BRIDGE_CFM_CC_CONFIG_MAX,
+};
+
+#define IFLA_BRIDGE_CFM_CC_CONFIG_MAX (__IFLA_BRIDGE_CFM_CC_CONFIG_MAX - 1)
+
+enum {
+	IFLA_BRIDGE_CFM_CC_PEER_MEP_UNSPEC,
+	IFLA_BRIDGE_CFM_CC_PEER_MEP_INSTANCE,
+	IFLA_BRIDGE_CFM_CC_PEER_MEPID,
+	__IFLA_BRIDGE_CFM_CC_PEER_MEP_MAX,
+};
+
+#define IFLA_BRIDGE_CFM_CC_PEER_MEP_MAX (__IFLA_BRIDGE_CFM_CC_PEER_MEP_MAX - 1)
+
+enum {
+	IFLA_BRIDGE_CFM_CC_RDI_UNSPEC,
+	IFLA_BRIDGE_CFM_CC_RDI_INSTANCE,
+	IFLA_BRIDGE_CFM_CC_RDI_RDI,
+	__IFLA_BRIDGE_CFM_CC_RDI_MAX,
+};
+
+#define IFLA_BRIDGE_CFM_CC_RDI_MAX (__IFLA_BRIDGE_CFM_CC_RDI_MAX - 1)
+
+enum {
+	IFLA_BRIDGE_CFM_CC_CCM_TX_UNSPEC,
+	IFLA_BRIDGE_CFM_CC_CCM_TX_INSTANCE,
+	IFLA_BRIDGE_CFM_CC_CCM_TX_DMAC,
+	IFLA_BRIDGE_CFM_CC_CCM_TX_SEQ_NO_UPDATE,
+	IFLA_BRIDGE_CFM_CC_CCM_TX_PERIOD,
+	IFLA_BRIDGE_CFM_CC_CCM_TX_IF_TLV,
+	IFLA_BRIDGE_CFM_CC_CCM_TX_IF_TLV_VALUE,
+	IFLA_BRIDGE_CFM_CC_CCM_TX_PORT_TLV,
+	IFLA_BRIDGE_CFM_CC_CCM_TX_PORT_TLV_VALUE,
+	__IFLA_BRIDGE_CFM_CC_CCM_TX_MAX,
+};
+
+#define IFLA_BRIDGE_CFM_CC_CCM_TX_MAX (__IFLA_BRIDGE_CFM_CC_CCM_TX_MAX - 1)
+
+enum {
+	IFLA_BRIDGE_CFM_MEP_STATUS_UNSPEC,
+	IFLA_BRIDGE_CFM_MEP_STATUS_INSTANCE,
+	IFLA_BRIDGE_CFM_MEP_STATUS_OPCODE_UNEXP_SEEN,
+	IFLA_BRIDGE_CFM_MEP_STATUS_VERSION_UNEXP_SEEN,
+	IFLA_BRIDGE_CFM_MEP_STATUS_RX_LEVEL_LOW_SEEN,
+	__IFLA_BRIDGE_CFM_MEP_STATUS_MAX,
+};
+
+#define IFLA_BRIDGE_CFM_MEP_STATUS_MAX (__IFLA_BRIDGE_CFM_MEP_STATUS_MAX - 1)
+
+enum {
+	IFLA_BRIDGE_CFM_CC_PEER_STATUS_UNSPEC,
+	IFLA_BRIDGE_CFM_CC_PEER_STATUS_INSTANCE,
+	IFLA_BRIDGE_CFM_CC_PEER_STATUS_PEER_MEPID,
+	IFLA_BRIDGE_CFM_CC_PEER_STATUS_CCM_DEFECT,
+	IFLA_BRIDGE_CFM_CC_PEER_STATUS_RDI,
+	IFLA_BRIDGE_CFM_CC_PEER_STATUS_PORT_TLV_VALUE,
+	IFLA_BRIDGE_CFM_CC_PEER_STATUS_IF_TLV_VALUE,
+	IFLA_BRIDGE_CFM_CC_PEER_STATUS_SEEN,
+	IFLA_BRIDGE_CFM_CC_PEER_STATUS_TLV_SEEN,
+	IFLA_BRIDGE_CFM_CC_PEER_STATUS_SEQ_UNEXP_SEEN,
+	__IFLA_BRIDGE_CFM_CC_PEER_STATUS_MAX,
+};
+
+#define IFLA_BRIDGE_CFM_CC_PEER_STATUS_MAX (__IFLA_BRIDGE_CFM_CC_PEER_STATUS_MAX - 1)
+
 struct bridge_stp_xstats {
 	__u64 transition_blk;
 	__u64 transition_fwd;

include/uapi/linux/if_ether.h

@@ -99,6 +99,7 @@
 #define ETH_P_1588	0x88F7		/* IEEE 1588 Timesync */
 #define ETH_P_NCSI	0x88F8		/* NCSI protocol		*/
 #define ETH_P_PRP	0x88FB		/* IEC 62439-3 PRP/HSRv0	*/
+#define ETH_P_CFM	0x8902		/* Connectivity Fault Management */
 #define ETH_P_FCOE	0x8906		/* Fibre Channel over Ethernet  */
 #define ETH_P_IBOE	0x8915		/* Infiniband over Ethernet	*/
 #define ETH_P_TDLS	0x890D          /* TDLS */

include/uapi/linux/rtnetlink.h

@@ -779,6 +779,8 @@ enum {
 #define RTEXT_FILTER_BRVLAN_COMPRESSED	(1 << 2)
 #define	RTEXT_FILTER_SKIP_STATS	(1 << 3)
 #define RTEXT_FILTER_MRP	(1 << 4)
+#define RTEXT_FILTER_CFM_CONFIG	(1 << 5)
+#define RTEXT_FILTER_CFM_STATUS	(1 << 6)
 
 /* End of information exported to user level */
 

net/bridge/Kconfig

@@ -73,3 +73,14 @@ config BRIDGE_MRP
 	  Say N to exclude this support and reduce the binary size.
 
 	  If unsure, say N.
+
+config BRIDGE_CFM
+	bool "CFM protocol"
+	depends on BRIDGE
+	help
+	  If you say Y here, then the Ethernet bridge will be able to run CFM
+	  protocol according to 802.1Q section 12.14
+
+	  Say N to exclude this support and reduce the binary size.
+
+	  If unsure, say N.

net/bridge/Makefile

@@ -27,3 +27,5 @@ bridge-$(CONFIG_NET_SWITCHDEV) += br_switchdev.o
 obj-$(CONFIG_NETFILTER) += netfilter/
 
 bridge-$(CONFIG_BRIDGE_MRP)	+= br_mrp_switchdev.o br_mrp.o br_mrp_netlink.o
+
+bridge-$(CONFIG_BRIDGE_CFM)	+= br_cfm.o br_cfm_netlink.o

net/bridge/br_device.c

@@ -454,8 +454,12 @@ void br_dev_setup(struct net_device *dev)
 	spin_lock_init(&br->lock);
 	INIT_LIST_HEAD(&br->port_list);
 	INIT_HLIST_HEAD(&br->fdb_list);
+	INIT_HLIST_HEAD(&br->frame_type_list);
 #if IS_ENABLED(CONFIG_BRIDGE_MRP)
 	INIT_LIST_HEAD(&br->mrp_list);
+#endif
+#if IS_ENABLED(CONFIG_BRIDGE_CFM)
+	INIT_HLIST_HEAD(&br->mep_list);
 #endif
 	spin_lock_init(&br->hash_lock);
 

net/bridge/br_if.c

@@ -334,6 +334,7 @@ static void del_nbp(struct net_bridge_port *p)
 	spin_unlock_bh(&br->lock);
 
 	br_mrp_port_del(br, p);
+	br_cfm_port_del(br, p);
 
 	br_ifinfo_notify(RTM_DELLINK, NULL, p);
 

net/bridge/br_input.c

@@ -254,6 +254,21 @@ static int nf_hook_bridge_pre(struct sk_buff *skb, struct sk_buff **pskb)
 	return RX_HANDLER_CONSUMED;
 }
 
+/* Return 0 if the frame was not processed otherwise 1
+ * note: already called with rcu_read_lock
+ */
+static int br_process_frame_type(struct net_bridge_port *p,
+				 struct sk_buff *skb)
+{
+	struct br_frame_type *tmp;
+
+	hlist_for_each_entry_rcu(tmp, &p->br->frame_type_list, list)
+		if (unlikely(tmp->type == skb->protocol))
+			return tmp->frame_handler(p, skb);
+
+	return 0;
+}
+
 /*
  * Return NULL if skb is handled
  * note: already called with rcu_read_lock
@@ -343,7 +358,7 @@ static rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
 		}
 	}
 
-	if (unlikely(br_mrp_process(p, skb)))
+	if (unlikely(br_process_frame_type(p, skb)))
 		return RX_HANDLER_PASS;
 
 forward:
@@ -380,3 +395,19 @@ rx_handler_func_t *br_get_rx_handler(const struct net_device *dev)
 
 	return br_handle_frame;
 }
+
+void br_add_frame(struct net_bridge *br, struct br_frame_type *ft)
+{
+	hlist_add_head_rcu(&ft->list, &br->frame_type_list);
+}
+
+void br_del_frame(struct net_bridge *br, struct br_frame_type *ft)
+{
+	struct br_frame_type *tmp;
+
+	hlist_for_each_entry(tmp, &br->frame_type_list, list)
+		if (ft == tmp) {
+			hlist_del_rcu(&ft->list);
+			return;
+		}
+}

net/bridge/br_mrp.c

@@ -6,6 +6,13 @@
 static const u8 mrp_test_dmac[ETH_ALEN] = { 0x1, 0x15, 0x4e, 0x0, 0x0, 0x1 };
 static const u8 mrp_in_test_dmac[ETH_ALEN] = { 0x1, 0x15, 0x4e, 0x0, 0x0, 0x3 };
 
+static int br_mrp_process(struct net_bridge_port *p, struct sk_buff *skb);
+
+static struct br_frame_type mrp_frame_type __read_mostly = {
+	.type = cpu_to_be16(ETH_P_MRP),
+	.frame_handler = br_mrp_process,
+};
+
 static bool br_mrp_is_ring_port(struct net_bridge_port *p_port,
 				struct net_bridge_port *s_port,
 				struct net_bridge_port *port)
@@ -445,6 +452,9 @@ static void br_mrp_del_impl(struct net_bridge *br, struct br_mrp *mrp)
 
 	list_del_rcu(&mrp->list);
 	kfree_rcu(mrp, rcu);
+
+	if (list_empty(&br->mrp_list))
+		br_del_frame(br, &mrp_frame_type);
 }
 
 /* Adds a new MRP instance.
@@ -493,6 +503,9 @@ int br_mrp_add(struct net_bridge *br, struct br_mrp_instance *instance)
 	spin_unlock_bh(&br->lock);
 	rcu_assign_pointer(mrp->s_port, p);
 
+	if (list_empty(&br->mrp_list))
+		br_add_frame(br, &mrp_frame_type);
+
 	INIT_DELAYED_WORK(&mrp->test_work, br_mrp_test_work_expired);
 	INIT_DELAYED_WORK(&mrp->in_test_work, br_mrp_in_test_work_expired);
 	list_add_tail_rcu(&mrp->list, &br->mrp_list);
@@ -1172,15 +1185,13 @@ static int br_mrp_rcv(struct net_bridge_port *p,
  * normal forwarding.
  * note: already called with rcu_read_lock
  */
-int br_mrp_process(struct net_bridge_port *p, struct sk_buff *skb)
+static int br_mrp_process(struct net_bridge_port *p, struct sk_buff *skb)
 {
 	/* If there is no MRP instance do normal forwarding */
 	if (likely(!(p->flags & BR_MRP_AWARE)))
 		goto out;
 
-	if (unlikely(skb->protocol == htons(ETH_P_MRP)))
-		return br_mrp_rcv(p, skb, p->dev);
-
+	return br_mrp_rcv(p, skb, p->dev);
 out:
 	return 0;
 }

net/bridge/br_netlink.c

@@ -16,6 +16,7 @@
 
 #include "br_private.h"
 #include "br_private_stp.h"
+#include "br_private_cfm.h"
 #include "br_private_tunnel.h"
 
 static int __get_num_vlan_infos(struct net_bridge_vlan_group *vg,
@@ -93,9 +94,11 @@ static size_t br_get_link_af_size_filtered(const struct net_device *dev,
 {
 	struct net_bridge_vlan_group *vg = NULL;
 	struct net_bridge_port *p = NULL;
-	struct net_bridge *br;
-	int num_vlan_infos;
+	struct net_bridge *br = NULL;
+	u32 num_cfm_peer_mep_infos;
+	u32 num_cfm_mep_infos;
 	size_t vinfo_sz = 0;
+	int num_vlan_infos;
 
 	rcu_read_lock();
 	if (netif_is_bridge_port(dev)) {
@@ -114,6 +117,49 @@ static size_t br_get_link_af_size_filtered(const struct net_device *dev,
 	/* Each VLAN is returned in bridge_vlan_info along with flags */
 	vinfo_sz += num_vlan_infos * nla_total_size(sizeof(struct bridge_vlan_info));
 
+	if (!(filter_mask & RTEXT_FILTER_CFM_STATUS))
+		return vinfo_sz;
+
+	if (!br)
+		return vinfo_sz;
+
+	/* CFM status info must be added */
+	br_cfm_mep_count(br, &num_cfm_mep_infos);
+	br_cfm_peer_mep_count(br, &num_cfm_peer_mep_infos);
+
+	vinfo_sz += nla_total_size(0);	/* IFLA_BRIDGE_CFM */
+	/* For each status struct the MEP instance (u32) is added */
+	/* MEP instance (u32) + br_cfm_mep_status */
+	vinfo_sz += num_cfm_mep_infos *
+		     /*IFLA_BRIDGE_CFM_MEP_STATUS_INSTANCE */
+		    (nla_total_size(sizeof(u32))
+		     /* IFLA_BRIDGE_CFM_MEP_STATUS_OPCODE_UNEXP_SEEN */
+		     + nla_total_size(sizeof(u32))
+		     /* IFLA_BRIDGE_CFM_MEP_STATUS_VERSION_UNEXP_SEEN */
+		     + nla_total_size(sizeof(u32))
+		     /* IFLA_BRIDGE_CFM_MEP_STATUS_RX_LEVEL_LOW_SEEN */
+		     + nla_total_size(sizeof(u32)));
+	/* MEP instance (u32) + br_cfm_cc_peer_status */
+	vinfo_sz += num_cfm_peer_mep_infos *
+		     /* IFLA_BRIDGE_CFM_CC_PEER_STATUS_INSTANCE */
+		    (nla_total_size(sizeof(u32))
+		     /* IFLA_BRIDGE_CFM_CC_PEER_STATUS_PEER_MEPID */
+		     + nla_total_size(sizeof(u32))
+		     /* IFLA_BRIDGE_CFM_CC_PEER_STATUS_CCM_DEFECT */
+		     + nla_total_size(sizeof(u32))
+		     /* IFLA_BRIDGE_CFM_CC_PEER_STATUS_RDI */
+		     + nla_total_size(sizeof(u32))
+		     /* IFLA_BRIDGE_CFM_CC_PEER_STATUS_PORT_TLV_VALUE */
+		     + nla_total_size(sizeof(u8))
+		     /* IFLA_BRIDGE_CFM_CC_PEER_STATUS_IF_TLV_VALUE */
+		     + nla_total_size(sizeof(u8))
+		     /* IFLA_BRIDGE_CFM_CC_PEER_STATUS_SEEN */
+		     + nla_total_size(sizeof(u32))
+		     /* IFLA_BRIDGE_CFM_CC_PEER_STATUS_TLV_SEEN */
+		     + nla_total_size(sizeof(u32))
+		     /* IFLA_BRIDGE_CFM_CC_PEER_STATUS_SEQ_UNEXP_SEEN */
+		     + nla_total_size(sizeof(u32)));
+
 	return vinfo_sz;
 }
 
@@ -377,7 +423,8 @@ static int br_fill_ifvlaninfo(struct sk_buff *skb,
 static int br_fill_ifinfo(struct sk_buff *skb,
 			  const struct net_bridge_port *port,
 			  u32 pid, u32 seq, int event, unsigned int flags,
-			  u32 filter_mask, const struct net_device *dev)
+			  u32 filter_mask, const struct net_device *dev,
+			  bool getlink)
 {
 	u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN;
 	struct nlattr *af = NULL;
@@ -426,7 +473,9 @@ static int br_fill_ifinfo(struct sk_buff *skb,
 
 	if (filter_mask & (RTEXT_FILTER_BRVLAN |
 			   RTEXT_FILTER_BRVLAN_COMPRESSED |
-			   RTEXT_FILTER_MRP)) {
+			   RTEXT_FILTER_MRP |
+			   RTEXT_FILTER_CFM_CONFIG |
+			   RTEXT_FILTER_CFM_STATUS)) {
 		af = nla_nest_start_noflag(skb, IFLA_AF_SPEC);
 		if (!af)
 			goto nla_put_failure;
@@ -475,6 +524,36 @@ static int br_fill_ifinfo(struct sk_buff *skb,
 			goto nla_put_failure;
 	}
 
+	if (filter_mask & (RTEXT_FILTER_CFM_CONFIG | RTEXT_FILTER_CFM_STATUS)) {
+		struct nlattr *cfm_nest = NULL;
+		int err;
+
+		if (!br_cfm_created(br) || port)
+			goto done;
+
+		cfm_nest = nla_nest_start(skb, IFLA_BRIDGE_CFM);
+		if (!cfm_nest)
+			goto nla_put_failure;
+
+		if (filter_mask & RTEXT_FILTER_CFM_CONFIG) {
+			rcu_read_lock();
+			err = br_cfm_config_fill_info(skb, br);
+			rcu_read_unlock();
+			if (err)
+				goto nla_put_failure;
+		}
+
+		if (filter_mask & RTEXT_FILTER_CFM_STATUS) {
+			rcu_read_lock();
+			err = br_cfm_status_fill_info(skb, br, getlink);
+			rcu_read_unlock();
+			if (err)
+				goto nla_put_failure;
+		}
+
+		nla_nest_end(skb, cfm_nest);
+	}
+
 done:
 	if (af)
 		nla_nest_end(skb, af);
@@ -486,11 +565,9 @@ static int br_fill_ifinfo(struct sk_buff *skb,
 	return -EMSGSIZE;
 }
 
-/* Notify listeners of a change in bridge or port information */
-void br_ifinfo_notify(int event, const struct net_bridge *br,
-		      const struct net_bridge_port *port)
+void br_info_notify(int event, const struct net_bridge *br,
+		    const struct net_bridge_port *port, u32 filter)
 {
-	u32 filter = RTEXT_FILTER_BRVLAN_COMPRESSED;
 	struct net_device *dev;
 	struct sk_buff *skb;
 	int err = -ENOBUFS;
@@ -515,7 +592,7 @@ void br_ifinfo_notify(int event, const struct net_bridge *br,
 	if (skb == NULL)
 		goto errout;
 
-	err = br_fill_ifinfo(skb, port, 0, 0, event, 0, filter, dev);
+	err = br_fill_ifinfo(skb, port, 0, 0, event, 0, filter, dev, false);
 	if (err < 0) {
 		/* -EMSGSIZE implies BUG in br_nlmsg_size() */
 		WARN_ON(err == -EMSGSIZE);
@@ -528,6 +605,15 @@ void br_ifinfo_notify(int event, const struct net_bridge *br,
 	rtnl_set_sk_err(net, RTNLGRP_LINK, err);
 }
 
+/* Notify listeners of a change in bridge or port information */
+void br_ifinfo_notify(int event, const struct net_bridge *br,
+		      const struct net_bridge_port *port)
+{
+	u32 filter = RTEXT_FILTER_BRVLAN_COMPRESSED;
+
+	return br_info_notify(event, br, port, filter);
+}
+
 /*
  * Dump information about all ports, in response to GETLINK
  */
@@ -538,11 +624,13 @@ int br_getlink(struct sk_buff *skb, u32 pid, u32 seq,
 
 	if (!port && !(filter_mask & RTEXT_FILTER_BRVLAN) &&
 	    !(filter_mask & RTEXT_FILTER_BRVLAN_COMPRESSED) &&
-	    !(filter_mask & RTEXT_FILTER_MRP))
+	    !(filter_mask & RTEXT_FILTER_MRP) &&
+	    !(filter_mask & RTEXT_FILTER_CFM_CONFIG) &&
+	    !(filter_mask & RTEXT_FILTER_CFM_STATUS))
 		return 0;
 
 	return br_fill_ifinfo(skb, port, pid, seq, RTM_NEWLINK, nlflags,
-			      filter_mask, dev);
+			      filter_mask, dev, true);
 }
 
 static int br_vlan_info(struct net_bridge *br, struct net_bridge_port *p,
@@ -700,6 +788,11 @@ static int br_afspec(struct net_bridge *br,
 			if (err)
 				return err;
 			break;
+		case IFLA_BRIDGE_CFM:
+			err = br_cfm_parse(br, p, attr, cmd, extack);
+			if (err)
+				return err;
+			break;
 		}
 	}
 

net/bridge/br_private.h

@@ -383,7 +383,7 @@ enum net_bridge_opts {
 struct net_bridge {
 	spinlock_t			lock;
 	spinlock_t			hash_lock;
-	struct list_head		port_list;
+	struct hlist_head		frame_type_list;
 	struct net_device		*dev;
 	struct pcpu_sw_netstats		__percpu *stats;
 	unsigned long			options;
@@ -395,6 +395,7 @@ struct net_bridge {
 #endif
 
 	struct rhashtable		fdb_hash_tbl;
+	struct list_head		port_list;
 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 	union {
 		struct rtable		fake_rtable;
@@ -483,6 +484,9 @@ struct net_bridge {
 #if IS_ENABLED(CONFIG_BRIDGE_MRP)
 	struct list_head		mrp_list;
 #endif
+#if IS_ENABLED(CONFIG_BRIDGE_CFM)
+	struct hlist_head		mep_list;
+#endif
 };
 
 struct br_input_skb_cb {
@@ -755,6 +759,16 @@ int nbp_backup_change(struct net_bridge_port *p, struct net_device *backup_dev);
 int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
 rx_handler_func_t *br_get_rx_handler(const struct net_device *dev);
 
+struct br_frame_type {
+	__be16			type;
+	int			(*frame_handler)(struct net_bridge_port *port,
+						 struct sk_buff *skb);
+	struct hlist_node	list;
+};
+
+void br_add_frame(struct net_bridge *br, struct br_frame_type *ft);
+void br_del_frame(struct net_bridge *br, struct br_frame_type *ft);
+
 static inline bool br_rx_handler_check_rcu(const struct net_device *dev)
 {
 	return rcu_dereference(dev->rx_handler) == br_get_rx_handler(dev);
@@ -1417,7 +1431,6 @@ extern int (*br_fdb_test_addr_hook)(struct net_device *dev, unsigned char *addr)
 #if IS_ENABLED(CONFIG_BRIDGE_MRP)
 int br_mrp_parse(struct net_bridge *br, struct net_bridge_port *p,
 		 struct nlattr *attr, int cmd, struct netlink_ext_ack *extack);
-int br_mrp_process(struct net_bridge_port *p, struct sk_buff *skb);
 bool br_mrp_enabled(struct net_bridge *br);
 void br_mrp_port_del(struct net_bridge *br, struct net_bridge_port *p);
 int br_mrp_fill_info(struct sk_buff *skb, struct net_bridge *br);
@@ -1429,11 +1442,6 @@ static inline int br_mrp_parse(struct net_bridge *br, struct net_bridge_port *p,
 	return -EOPNOTSUPP;
 }
 
-static inline int br_mrp_process(struct net_bridge_port *p, struct sk_buff *skb)
-{
-	return 0;
-}
-
 static inline bool br_mrp_enabled(struct net_bridge *br)
 {
 	return false;
@@ -1451,12 +1459,67 @@ static inline int br_mrp_fill_info(struct sk_buff *skb, struct net_bridge *br)
 
 #endif
 
+/* br_cfm.c */
+#if IS_ENABLED(CONFIG_BRIDGE_CFM)
+int br_cfm_parse(struct net_bridge *br, struct net_bridge_port *p,
+		 struct nlattr *attr, int cmd, struct netlink_ext_ack *extack);
+bool br_cfm_created(struct net_bridge *br);
+void br_cfm_port_del(struct net_bridge *br, struct net_bridge_port *p);
+int br_cfm_config_fill_info(struct sk_buff *skb, struct net_bridge *br);
+int br_cfm_status_fill_info(struct sk_buff *skb,
+			    struct net_bridge *br,
+			    bool getlink);
+int br_cfm_mep_count(struct net_bridge *br, u32 *count);
+int br_cfm_peer_mep_count(struct net_bridge *br, u32 *count);
+#else
+static inline int br_cfm_parse(struct net_bridge *br, struct net_bridge_port *p,
+			       struct nlattr *attr, int cmd,
+			       struct netlink_ext_ack *extack)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline bool br_cfm_created(struct net_bridge *br)
+{
+	return false;
+}
+
+static inline void br_cfm_port_del(struct net_bridge *br,
+				   struct net_bridge_port *p)
+{
+}
+
+static inline int br_cfm_config_fill_info(struct sk_buff *skb, struct net_bridge *br)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int br_cfm_status_fill_info(struct sk_buff *skb,
+					  struct net_bridge *br,
+					  bool getlink)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int br_cfm_mep_count(struct net_bridge *br, u32 *count)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int br_cfm_peer_mep_count(struct net_bridge *br, u32 *count)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
 /* br_netlink.c */
 extern struct rtnl_link_ops br_link_ops;
 int br_netlink_init(void);
 void br_netlink_fini(void);
 void br_ifinfo_notify(int event, const struct net_bridge *br,
 		      const struct net_bridge_port *port);
+void br_info_notify(int event, const struct net_bridge *br,
+		    const struct net_bridge_port *port, u32 filter);
 int br_setlink(struct net_device *dev, struct nlmsghdr *nlmsg, u16 flags,
 	       struct netlink_ext_ack *extack);
 int br_dellink(struct net_device *dev, struct nlmsghdr *nlmsg, u16 flags);

net/bridge/br_private_cfm.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _BR_PRIVATE_CFM_H_
+#define _BR_PRIVATE_CFM_H_
+
+#include "br_private.h"
+#include <uapi/linux/cfm_bridge.h>
+
+struct br_cfm_mep_create {
+	enum br_cfm_domain domain; /* Domain for this MEP */
+	enum br_cfm_mep_direction direction; /* Up or Down MEP direction */
+	u32 ifindex; /* Residence port */
+};
+
+int br_cfm_mep_create(struct net_bridge *br,
+		      const u32 instance,
+		      struct br_cfm_mep_create *const create,
+		      struct netlink_ext_ack *extack);
+
+int br_cfm_mep_delete(struct net_bridge *br,
+		      const u32 instance,
+		      struct netlink_ext_ack *extack);
+
+struct br_cfm_mep_config {
+	u32 mdlevel;
+	u32 mepid; /* MEPID for this MEP */
+	struct mac_addr unicast_mac; /* The MEP unicast MAC */
+};
+
+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_maid {
+	u8 data[CFM_MAID_LENGTH];
+};
+
+struct br_cfm_cc_config {
+	/* Expected received CCM PDU MAID. */
+	struct br_cfm_maid exp_maid;
+
+	/* Expected received CCM PDU interval. */
+	/* Transmitting CCM PDU interval when CCM tx is enabled. */
+	enum br_cfm_ccm_interval exp_interval;
+
+	bool enable; /* Enable/disable CCM PDU handling */
+};
+
+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);
+
+int br_cfm_cc_peer_mep_add(struct net_bridge *br, const u32 instance,
+			   u32 peer_mep_id,
+			   struct netlink_ext_ack *extack);
+int br_cfm_cc_peer_mep_remove(struct net_bridge *br, const u32 instance,
+			      u32 peer_mep_id,
+			      struct netlink_ext_ack *extack);
+
+/* Transmitted CCM Remote Defect Indication status set.
+ * This RDI is inserted in transmitted CCM PDUs if CCM transmission is enabled.
+ * See br_cfm_cc_ccm_tx() with interval != BR_CFM_CCM_INTERVAL_NONE
+ */
+int br_cfm_cc_rdi_set(struct net_bridge *br, const u32 instance,
+		      const bool rdi, struct netlink_ext_ack *extack);
+
+/* OAM PDU Tx information */
+struct br_cfm_cc_ccm_tx_info {
+	struct mac_addr dmac;
+	/* The CCM will be transmitted for this period in seconds.
+	 * Call br_cfm_cc_ccm_tx before timeout to keep transmission alive.
+	 * When period is zero any ongoing transmission will be stopped.
+	 */
+	u32 period;
+
+	bool seq_no_update; /* Update Tx CCM sequence number */
+	bool if_tlv; /* Insert Interface Status TLV */
+	u8 if_tlv_value; /* Interface Status TLV value */
+	bool port_tlv; /* Insert Port Status TLV */
+	u8 port_tlv_value; /* Port Status TLV value */
+	/* Sender ID TLV ??
+	 * Organization-Specific TLV ??
+	 */
+};
+
+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_status {
+	/* Indications that an OAM PDU has been seen. */
+	bool opcode_unexp_seen; /* RX of OAM PDU with unexpected opcode */
+	bool version_unexp_seen; /* RX of OAM PDU with unexpected version */
+	bool rx_level_low_seen; /* Rx of OAM PDU with level low */
+};
+
+struct br_cfm_cc_peer_status {
+	/* This CCM related status is based on the latest received CCM PDU. */
+	u8 port_tlv_value; /* Port Status TLV value */
+	u8 if_tlv_value; /* Interface Status TLV value */
+
+	/* CCM has not been received for 3.25 intervals */
+	u8 ccm_defect:1;
+
+	/* (RDI == 1) for last received CCM PDU */
+	u8 rdi:1;
+
+	/* Indications that a CCM PDU has been seen. */
+	u8 seen:1; /* CCM PDU received */
+	u8 tlv_seen:1; /* CCM PDU with TLV received */
+	/* CCM PDU with unexpected sequence number received */
+	u8 seq_unexp_seen:1;
+};
+
+struct br_cfm_mep {
+	/* list header of MEP instances */
+	struct hlist_node		head;
+	u32				instance;
+	struct br_cfm_mep_create	create;
+	struct br_cfm_mep_config	config;
+	struct br_cfm_cc_config		cc_config;
+	struct br_cfm_cc_ccm_tx_info	cc_ccm_tx_info;
+	/* List of multiple peer MEPs */
+	struct hlist_head		peer_mep_list;
+	struct net_bridge_port __rcu	*b_port;
+	unsigned long			ccm_tx_end;
+	struct delayed_work		ccm_tx_dwork;
+	u32				ccm_tx_snumber;
+	u32				ccm_rx_snumber;
+	struct br_cfm_mep_status	status;
+	bool				rdi;
+	struct rcu_head			rcu;
+};
+
+struct br_cfm_peer_mep {
+	struct hlist_node		head;
+	struct br_cfm_mep		*mep;
+	struct delayed_work		ccm_rx_dwork;
+	u32				mepid;
+	struct br_cfm_cc_peer_status	cc_status;
+	u32				ccm_rx_count_miss;
+	struct rcu_head			rcu;
+};
+
+#endif /* _BR_PRIVATE_CFM_H_ */