This patch added two more mibs for MP_FASTCLOSE, MPTCP_MIB_MPFASTCLOSETX
for the MP_FASTCLOSE sending and MPTCP_MIB_MPFASTCLOSERX for receiving.

Also added a debug log for MP_FASTCLOSE receiving, printed out the recv_key
of MP_FASTCLOSE in mptcp_parse_option to show that MP_RST is received.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 net/mptcp/mib.c     | 2 ++
 net/mptcp/mib.h     | 2 ++
 net/mptcp/options.c | 3 +++
 3 files changed, 7 insertions(+)

diff --git a/net/mptcp/mib.c b/net/mptcp/mib.c
index 7cef7409e300..684643f8af53 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("MPFastcloseTx", MPTCP_MIB_MPFASTCLOSETX),
+	SNMP_MIB_ITEM("MPFastcloseRx", MPTCP_MIB_MPFASTCLOSERX),
 	SNMP_MIB_ITEM("RcvPruned", MPTCP_MIB_RCVPRUNED),
 	SNMP_MIB_ITEM("SubflowStale", MPTCP_MIB_SUBFLOWSTALE),
 	SNMP_MIB_ITEM("SubflowRecover", MPTCP_MIB_SUBFLOWRECOVER),
diff --git a/net/mptcp/mib.h b/net/mptcp/mib.h
index 785cf751e5c0..93dd5176fd5e 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_MPFASTCLOSETX,	/* Transmit a MP_FASTCLOSE */
+	MPTCP_MIB_MPFASTCLOSERX,	/* Received a MP_FASTCLOSE */
 	MPTCP_MIB_RCVPRUNED,		/* Incoming packet dropped due to memory limit */
 	MPTCP_MIB_SUBFLOWSTALE,		/* Subflows entered 'stale' status */
 	MPTCP_MIB_SUBFLOWRECOVER,	/* Subflows returned to active status after being stale */
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 0401b22128c4..e775d75807fd 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -323,6 +323,7 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 		mp_opt->rcvr_key = get_unaligned_be64(ptr);
 		ptr += 8;
 		mp_opt->suboptions |= OPTION_MPTCP_FASTCLOSE;
+		pr_debug("MP_FASTCLOSE: recv_key=%llu", mp_opt->rcvr_key);
 		break;
 
 	case MPTCPOPT_RST:
@@ -832,6 +833,7 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
 		    mptcp_established_options_mp_fail(sk, &opt_size, remaining, opts)) {
 			*size += opt_size;
 			remaining -= opt_size;
+			MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFASTCLOSETX);
 		}
 		/* MP_RST can be used with MP_FASTCLOSE and MP_FAIL if there is room */
 		if (mptcp_established_options_rst(sk, skb, &opt_size, remaining, opts)) {
@@ -1124,6 +1126,7 @@ bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
 		    msk->local_key == mp_opt.rcvr_key) {
 			WRITE_ONCE(msk->rcv_fastclose, true);
 			mptcp_schedule_work((struct sock *)msk);
+			MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFASTCLOSERX);
 		}
 
 		if ((mp_opt.suboptions & OPTION_MPTCP_ADD_ADDR) &&
-- 
2.34.1