[PATCH net-next 05/11] mptcp: add per-event MIB counters for MPTCP_RST_EMPTCP resets

@@ -21,14 +21,19 @@ static const struct snmp_mib mptcp_snmp_list[] = {
 	SNMP_MIB_ITEM("MPFallbackTokenInit", MPTCP_MIB_TOKENFALLBACKINIT),
 	SNMP_MIB_ITEM("MPTCPRetrans", MPTCP_MIB_RETRANSSEGS),
 	SNMP_MIB_ITEM("MPJoinNoTokenFound", MPTCP_MIB_JOINNOTOKEN),
+	SNMP_MIB_ITEM("MPJoinNoIdFound", MPTCP_MIB_MPJOINNOIDFOUND),
 	SNMP_MIB_ITEM("MPJoinSynRx", MPTCP_MIB_JOINSYNRX),
 	SNMP_MIB_ITEM("MPJoinSynBackupRx", MPTCP_MIB_JOINSYNBACKUPRX),
 	SNMP_MIB_ITEM("MPJoinSynAckRx", MPTCP_MIB_JOINSYNACKRX),
 	SNMP_MIB_ITEM("MPJoinSynAckBackupRx", MPTCP_MIB_JOINSYNACKBACKUPRX),
 	SNMP_MIB_ITEM("MPJoinSynAckHMacFailure", MPTCP_MIB_JOINSYNACKMAC),
+	SNMP_MIB_ITEM("MPJoinSynAckNoMPJoin", MPTCP_MIB_MPJOINSYNACKNOMPJOIN),
 	SNMP_MIB_ITEM("MPJoinAckRx", MPTCP_MIB_JOINACKRX),
 	SNMP_MIB_ITEM("MPJoinAckHMacFailure", MPTCP_MIB_JOINACKMAC),
+	SNMP_MIB_ITEM("MPJoinAckNoMPJoin", MPTCP_MIB_MPJOINACKNOMPJOIN),
+	SNMP_MIB_ITEM("MPJoinAckNoCtx", MPTCP_MIB_MPJOINACKNOCTX),
 	SNMP_MIB_ITEM("MPJoinRejected", MPTCP_MIB_JOINREJECTED),
+	SNMP_MIB_ITEM("MPJoinNotEstablished", MPTCP_MIB_MPJOINNOTESTABLISHED),
 	SNMP_MIB_ITEM("MPJoinSynTx", MPTCP_MIB_JOINSYNTX),
 	SNMP_MIB_ITEM("MPJoinSynTxCreatSkErr", MPTCP_MIB_JOINSYNTXCREATSKERR),
 	SNMP_MIB_ITEM("MPJoinSynTxBindErr", MPTCP_MIB_JOINSYNTXBINDERR),

@@ -81,7 +86,9 @@ static const struct snmp_mib mptcp_snmp_list[] = {
 	SNMP_MIB_ITEM("Blackhole", MPTCP_MIB_BLACKHOLE),
 	SNMP_MIB_ITEM("MPCapableDataFallback", MPTCP_MIB_MPCAPABLEDATAFALLBACK),
 	SNMP_MIB_ITEM("MD5SigFallback", MPTCP_MIB_MD5SIGFALLBACK),
+	SNMP_MIB_ITEM("MD5SigReset", MPTCP_MIB_MD5SIGRESET),
 	SNMP_MIB_ITEM("DssFallback", MPTCP_MIB_DSSFALLBACK),
+	SNMP_MIB_ITEM("DssReset", MPTCP_MIB_DSSRESET),
 	SNMP_MIB_ITEM("SimultConnectFallback", MPTCP_MIB_SIMULTCONNFALLBACK),
 	SNMP_MIB_ITEM("FallbackFailed", MPTCP_MIB_FALLBACKFAILED),
 	SNMP_MIB_ITEM("WinProbe", MPTCP_MIB_WINPROBE),

@@ -16,14 +16,19 @@ enum linux_mptcp_mib_field {
 	MPTCP_MIB_TOKENFALLBACKINIT,	/* Could not init/allocate token */
 	MPTCP_MIB_RETRANSSEGS,		/* Segments retransmitted at the MPTCP-level */
 	MPTCP_MIB_JOINNOTOKEN,		/* Received MP_JOIN but the token was not found */
+	MPTCP_MIB_MPJOINNOIDFOUND,	/* Received MP_JOIN but no local ID was found */
 	MPTCP_MIB_JOINSYNRX,		/* Received a SYN + MP_JOIN */
 	MPTCP_MIB_JOINSYNBACKUPRX,	/* Received a SYN + MP_JOIN + backup flag */
 	MPTCP_MIB_JOINSYNACKRX,		/* Received a SYN/ACK + MP_JOIN */
 	MPTCP_MIB_JOINSYNACKBACKUPRX,	/* Received a SYN/ACK + MP_JOIN + backup flag */
 	MPTCP_MIB_JOINSYNACKMAC,	/* HMAC was wrong on SYN/ACK + MP_JOIN */
+	MPTCP_MIB_MPJOINSYNACKNOMPJOIN,	/* MP_RST: missing MP_JOIN in SYN/ACK */
 	MPTCP_MIB_JOINACKRX,		/* Received an ACK + MP_JOIN */
 	MPTCP_MIB_JOINACKMAC,		/* HMAC was wrong on ACK + MP_JOIN */
+	MPTCP_MIB_MPJOINACKNOMPJOIN,	/* MP_RST: missing MP_JOIN in ACK */
+	MPTCP_MIB_MPJOINACKNOCTX,	/* MP_RST: no subflow context on ACK */
 	MPTCP_MIB_JOINREJECTED,		/* The PM rejected the JOIN request */
+	MPTCP_MIB_MPJOINNOTESTABLISHED,	/* MP_RST: JOIN on not-fully-established msk */
 	MPTCP_MIB_JOINSYNTX,		/* Sending a SYN + MP_JOIN */
 	MPTCP_MIB_JOINSYNTXCREATSKERR,	/* Not able to create a socket when sending a SYN + MP_JOIN */
 	MPTCP_MIB_JOINSYNTXBINDERR,	/* Not able to bind() the address when sending a SYN + MP_JOIN */

@@ -84,7 +89,9 @@ enum linux_mptcp_mib_field {
 					 * established packet
 					 */
 	MPTCP_MIB_MD5SIGFALLBACK,	/* Conflicting TCP option enabled */
+	MPTCP_MIB_MD5SIGRESET,		/* MP_RST: MD5SIG enabled on listener */
 	MPTCP_MIB_DSSFALLBACK,		/* Bad or missing DSS */
+	MPTCP_MIB_DSSRESET,		/* MP_RST: bad data mapping */
 	MPTCP_MIB_SIMULTCONNFALLBACK,	/* Simultaneous connect */
 	MPTCP_MIB_FALLBACKFAILED,	/* Can't fallback due to msk status */
 	MPTCP_MIB_WINPROBE,		/* MPTCP-level zero window probe */

@@ -4002,6 +4002,7 @@ bool mptcp_finish_join(struct sock *ssk)
 
 	/* mptcp socket already closing? */
 	if (!mptcp_is_fully_established(parent)) {
+		MPTCP_INC_STATS(sock_net(parent), MPTCP_MIB_MPJOINNOTESTABLISHED);
 		subflow->reset_reason = MPTCP_RST_EMPTCP;
 		return false;
 	}

@@ -96,6 +96,7 @@ static struct mptcp_sock *subflow_token_join_request(struct request_sock *req)
 
 	local_id = mptcp_pm_get_local_id(msk, (struct sock_common *)req);
 	if (local_id < 0) {
+		SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPJOINNOIDFOUND);
 		sock_put((struct sock *)msk);
 		return NULL;
 	}

@@ -160,6 +161,7 @@ static int subflow_check_req(struct request_sock *req,
 	 * TCP option space.
 	 */
 	if (rcu_access_pointer(tcp_sk(sk_listener)->md5sig_info)) {
+		MPTCP_INC_STATS(sock_net(sk_listener), MPTCP_MIB_MD5SIGRESET);
 		subflow_add_reset_reason(skb, MPTCP_RST_EMPTCP);
 		return -EINVAL;
 	}

@@ -563,6 +565,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 		u8 hmac[SHA256_DIGEST_SIZE];
 
 		if (!(mp_opt.suboptions & OPTION_MPTCP_MPJ_SYNACK)) {
+			MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPJOINSYNACKNOMPJOIN);
 			subflow->reset_reason = MPTCP_RST_EMPTCP;
 			goto do_reset;
 		}

@@ -865,6 +868,12 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
 		 */
 		if (!ctx || fallback) {
 			if (fallback_is_fatal) {
+				if (!ctx)
+					MPTCP_INC_STATS(sock_net(sk),
+							MPTCP_MIB_MPJOINACKNOCTX);
+				else
+					MPTCP_INC_STATS(sock_net(sk),
+							MPTCP_MIB_MPJOINACKNOMPJOIN);
 				subflow_add_reset_reason(skb, MPTCP_RST_EMPTCP);
 				goto dispose_child;
 			}

@@ -1416,6 +1425,7 @@ static bool subflow_check_data_avail(struct sock *ssk)
 			 * subflow_error_report() will introduce the appropriate barriers
 			 */
 			subflow->reset_transient = 0;
+			MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSRESET);
 			subflow->reset_reason = status == MAPPING_NODSS ?
 						MPTCP_RST_EMIDDLEBOX :
 						MPTCP_RST_EMPTCP;