Add MP_FAIL echo support.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 net/mptcp/mib.c | 2 ++
 net/mptcp/mib.h | 2 ++
 net/mptcp/pm.c  | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/net/mptcp/mib.c b/net/mptcp/mib.c
index d93a8c9996fd..f3070daa013b 100644
--- a/net/mptcp/mib.c
+++ b/net/mptcp/mib.c
@@ -49,6 +49,8 @@ static const struct snmp_mib mptcp_snmp_list[] = {
 	SNMP_MIB_ITEM("MPPrioRx", MPTCP_MIB_MPPRIORX),
 	SNMP_MIB_ITEM("MPFailTx", MPTCP_MIB_MPFAILTX),
 	SNMP_MIB_ITEM("MPFailRx", MPTCP_MIB_MPFAILRX),
+	SNMP_MIB_ITEM("MPFailEchoTx", MPTCP_MIB_MPFAILECHOTX),
+	SNMP_MIB_ITEM("MPFailEchoRx", MPTCP_MIB_MPFAILECHORX),
 	SNMP_MIB_ITEM("MPFastcloseTx", MPTCP_MIB_MPFASTCLOSETX),
 	SNMP_MIB_ITEM("MPFastcloseRx", MPTCP_MIB_MPFASTCLOSERX),
 	SNMP_MIB_ITEM("MPRstTx", MPTCP_MIB_MPRSTTX),
diff --git a/net/mptcp/mib.h b/net/mptcp/mib.h
index 529d07af9e14..83219721d337 100644
--- a/net/mptcp/mib.h
+++ b/net/mptcp/mib.h
@@ -42,6 +42,8 @@ enum linux_mptcp_mib_field {
 	MPTCP_MIB_MPPRIORX,		/* Received a MP_PRIO */
 	MPTCP_MIB_MPFAILTX,		/* Transmit a MP_FAIL */
 	MPTCP_MIB_MPFAILRX,		/* Received a MP_FAIL */
+	MPTCP_MIB_MPFAILECHOTX,		/* Transmit a MP_FAIL echo */
+	MPTCP_MIB_MPFAILECHORX,		/* Received a MP_FAIL echo */
 	MPTCP_MIB_MPFASTCLOSETX,	/* Transmit a MP_FASTCLOSE */
 	MPTCP_MIB_MPFASTCLOSERX,	/* Received a MP_FASTCLOSE */
 	MPTCP_MIB_MPRSTTX,		/* Transmit a MP_RST */
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index dc0dffc1b6b5..314e110588d7 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -283,8 +283,10 @@ void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq)
 		if (!subflow->mp_fail_response_expect) {
 			subflow->send_mp_fail = 1;
 			subflow->send_infinite_map = 1;
+			MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFAILECHOTX);
 		} else {
 			subflow->mp_fail_response_expect = 0;
+			MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFAILECHORX);
 		}
 	}
 }
-- 
2.34.1