diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index e6391e234e97..368fae525fea 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -247,6 +247,22 @@ is_v6()
 	[ -z "${1##*:*}" ]
 }
 
+# $1: ns ; $2: counter
+get_counter()
+{
+	local ns="${1}"
+	local counter="${2}"
+	local count
+
+	count=$(ip netns exec ${ns} nstat -asz "${counter}" | awk 'NR==1 {next} {print $2}')
+	if [ -z "${count}" ]; then
+		mptcp_lib_fail_if_expected_feature "${counter} counter"
+		return 1
+	fi
+
+	echo "${count}"
+}
+
 do_transfer()
 {
 	listener_ns="$1"
@@ -560,9 +576,10 @@ chk_csum_nr()
 		echo -n "  "
 	fi
 	printf " %-36s %s" "$msg" "sum"
-	count=`ip netns exec $ns1 nstat -as | grep MPTcpExtDataCsumErr | awk '{print $2}'`
-	[ -z "$count" ] && count=0
-	if [ "$count" != 0 ]; then
+	count=$(get_counter ${ns1} "MPTcpExtDataCsumErr")
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif [ "$count" != 0 ]; then
 		echo "[fail] got $count data checksum error[s] expected 0"
 		ret=1
 		dump_stats=1
@@ -570,9 +587,10 @@ chk_csum_nr()
 		echo -n "[ ok ]"
 	fi
 	echo -n " - csum  "
-	count=`ip netns exec $ns2 nstat -as | grep MPTcpExtDataCsumErr | awk '{print $2}'`
-	[ -z "$count" ] && count=0
-	if [ "$count" != 0 ]; then
+	count=$(get_counter ${ns2} "MPTcpExtDataCsumErr")
+	if [ -z "$count" ]; then
+		echo "[skip]"
+	elif [ "$count" != 0 ]; then
 		echo "[fail] got $count data checksum error[s] expected 0"
 		ret=1
 		dump_stats=1
@@ -595,9 +613,10 @@ chk_fail_nr()
 	local dump_stats
 
 	printf "%-39s %s" " " "ftx"
-	count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPFailTx | awk '{print $2}'`
-	[ -z "$count" ] && count=0
-	if [ "$count" != "$mp_fail_nr_tx" ]; then
+	count=$(get_counter ${ns1} "MPTcpExtMPFailTx")
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif [ "$count" != "$mp_fail_nr_tx" ]; then
 		echo "[fail] got $count MP_FAIL[s] TX expected $mp_fail_nr_tx"
 		ret=1
 		dump_stats=1
@@ -606,9 +625,10 @@ chk_fail_nr()
 	fi
 
 	echo -n " - frx   "
-	count=`ip netns exec $ns2 nstat -as | grep MPTcpExtMPFailRx | awk '{print $2}'`
-	[ -z "$count" ] && count=0
-	if [ "$count" != "$mp_fail_nr_rx" ]; then
+	count=$(get_counter ${ns2} "MPTcpExtMPFailRx")
+	if [ -z "$count" ]; then
+		echo "[skip]"
+	elif [ "$count" != "$mp_fail_nr_rx" ]; then
 		echo "[fail] got $count MP_FAIL[s] RX expected $mp_fail_nr_rx"
 		ret=1
 		dump_stats=1
@@ -635,9 +655,10 @@ chk_join_nr()
 	local with_cookie
 
 	printf "%02u %-36s %s" "$TEST_COUNT" "$msg" "syn"
-	count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinSynRx | awk '{print $2}'`
-	[ -z "$count" ] && count=0
-	if [ "$count" != "$syn_nr" ]; then
+	count=$(get_counter ${ns1} "MPTcpExtMPJoinSynRx")
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif [ "$count" != "$syn_nr" ]; then
 		echo "[fail] got $count JOIN[s] syn expected $syn_nr"
 		ret=1
 		dump_stats=1
@@ -647,9 +668,10 @@ chk_join_nr()
 
 	echo -n " - synack"
 	with_cookie=`ip netns exec $ns2 sysctl -n net.ipv4.tcp_syncookies`
-	count=`ip netns exec $ns2 nstat -as | grep MPTcpExtMPJoinSynAckRx | awk '{print $2}'`
-	[ -z "$count" ] && count=0
-	if [ "$count" != "$syn_ack_nr" ]; then
+	count=$(get_counter ${ns2} "MPTcpExtMPJoinSynAckRx")
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif [ "$count" != "$syn_ack_nr" ]; then
 		# simult connections exceeding the limit with cookie enabled could go up to
 		# synack validation as the conn limit can be enforced reliably only after
 		# the subflow creation
@@ -665,9 +687,10 @@ chk_join_nr()
 	fi
 
 	echo -n " - ack"
-	count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinAckRx | awk '{print $2}'`
-	[ -z "$count" ] && count=0
-	if [ "$count" != "$ack_nr" ]; then
+	count=$(get_counter ${ns1} "MPTcpExtMPJoinAckRx")
+	if [ -z "$count" ]; then
+		echo "[skip]"
+	elif [ "$count" != "$ack_nr" ]; then
 		echo "[fail] got $count JOIN[s] ack expected $ack_nr"
 		ret=1
 		dump_stats=1
@@ -702,14 +725,13 @@ chk_stale_nr()
 	local recover_nr
 
 	printf "%-39s %-18s" " " "stale"
-	stale_nr=`ip netns exec $ns nstat -as | grep MPTcpExtSubflowStale | awk '{print $2}'`
-	[ -z "$stale_nr" ] && stale_nr=0
-	recover_nr=`ip netns exec $ns nstat -as | grep MPTcpExtSubflowRecover | awk '{print $2}'`
-	[ -z "$recover_nr" ] && recover_nr=0
-
-	if [ $stale_nr -lt $stale_min ] ||
-	   [ $stale_max -gt 0 -a $stale_nr -gt $stale_max ] ||
-	   [ $((stale_nr - $recover_nr)) -ne $stale_delta ]; then
+	stale_nr=$(get_counter ${ns} "MPTcpExtSubflowStale")
+	recover_nr=$(get_counter ${ns} "MPTcpExtSubflowRecover")
+	if [ -z "$stale_nr" ] || [ -z "$recover_nr" ]; then
+		echo "[skip]"
+	elif [ $stale_nr -lt $stale_min ] ||
+	     [ $stale_max -gt 0 -a $stale_nr -gt $stale_max ] ||
+	     [ $((stale_nr - $recover_nr)) -ne $stale_delta ]; then
 		echo "[fail] got $stale_nr stale[s] $recover_nr recover[s], " \
 		     " expected stale in range [$stale_min..$stale_max]," \
 		     " stale-recover delta $stale_delta "
@@ -740,9 +762,10 @@ chk_add_nr()
 	local dump_stats
 
 	printf "%-39s %s" " " "add"
-	count=`ip netns exec $ns2 nstat -as MPTcpExtAddAddr | grep MPTcpExtAddAddr | awk '{print $2}'`
-	[ -z "$count" ] && count=0
-	if [ "$count" != "$add_nr" ]; then
+	count=$(get_counter ${ns2} "MPTcpExtAddAddr")
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif [ "$count" != "$add_nr" ]; then
 		echo "[fail] got $count ADD_ADDR[s] expected $add_nr"
 		ret=1
 		dump_stats=1
@@ -751,9 +774,10 @@ chk_add_nr()
 	fi
 
 	echo -n " - echo  "
-	count=`ip netns exec $ns1 nstat -as | grep MPTcpExtEchoAdd | awk '{print $2}'`
-	[ -z "$count" ] && count=0
-	if [ "$count" != "$echo_nr" ]; then
+	count=$(get_counter ${ns1} "MPTcpExtEchoAdd")
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif [ "$count" != "$echo_nr" ]; then
 		echo "[fail] got $count ADD_ADDR echo[s] expected $echo_nr"
 		ret=1
 		dump_stats=1
@@ -763,9 +787,10 @@ chk_add_nr()
 
 	if [ $port_nr -gt 0 ]; then
 		echo -n " - pt "
-		count=`ip netns exec $ns2 nstat -as | grep MPTcpExtPortAdd | awk '{print $2}'`
-		[ -z "$count" ] && count=0
-		if [ "$count" != "$port_nr" ]; then
+		count=$(get_counter ${ns2} "MPTcpExtPortAdd")
+		if [ -z "$count" ]; then
+			echo "[skip]"
+		elif [ "$count" != "$port_nr" ]; then
 			echo "[fail] got $count ADD_ADDR[s] with a port-number expected $port_nr"
 			ret=1
 			dump_stats=1
@@ -774,10 +799,10 @@ chk_add_nr()
 		fi
 
 		printf "%-39s %s" " " "syn"
-		count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinPortSynRx |
-			awk '{print $2}'`
-		[ -z "$count" ] && count=0
-		if [ "$count" != "$syn_nr" ]; then
+		count=$(get_counter ${ns1} "MPTcpExtMPJoinPortSynRx")
+		if [ -z "$count" ]; then
+			echo -n "[skip]"
+		elif [ "$count" != "$syn_nr" ]; then
 			echo "[fail] got $count JOIN[s] syn with a different \
 				port-number expected $syn_nr"
 			ret=1
@@ -787,10 +812,10 @@ chk_add_nr()
 		fi
 
 		echo -n " - synack"
-		count=`ip netns exec $ns2 nstat -as | grep MPTcpExtMPJoinPortSynAckRx |
-			awk '{print $2}'`
-		[ -z "$count" ] && count=0
-		if [ "$count" != "$syn_ack_nr" ]; then
+		count=$(get_counter ${ns2} "MPTcpExtMPJoinPortSynAckRx")
+		if [ -z "$count" ]; then
+			echo -n "[skip]"
+		elif [ "$count" != "$syn_ack_nr" ]; then
 			echo "[fail] got $count JOIN[s] synack with a different \
 				port-number expected $syn_ack_nr"
 			ret=1
@@ -800,10 +825,10 @@ chk_add_nr()
 		fi
 
 		echo -n " - ack"
-		count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinPortAckRx |
-			awk '{print $2}'`
-		[ -z "$count" ] && count=0
-		if [ "$count" != "$ack_nr" ]; then
+		count=$(get_counter ${ns1} "MPTcpExtMPJoinPortAckRx")
+		if [ -z "$count" ]; then
+			echo "[skip]"
+		elif [ "$count" != "$ack_nr" ]; then
 			echo "[fail] got $count JOIN[s] ack with a different \
 				port-number expected $ack_nr"
 			ret=1
@@ -813,10 +838,10 @@ chk_add_nr()
 		fi
 
 		printf "%-39s %s" " " "syn"
-		count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMismatchPortSynRx |
-			awk '{print $2}'`
-		[ -z "$count" ] && count=0
-		if [ "$count" != "$mis_syn_nr" ]; then
+		count=$(get_counter ${ns1} "MPTcpExtMismatchPortSynRx")
+		if [ -z "$count" ]; then
+			echo -n "[skip]"
+		elif [ "$count" != "$mis_syn_nr" ]; then
 			echo "[fail] got $count JOIN[s] syn with a mismatched \
 				port-number expected $mis_syn_nr"
 			ret=1
@@ -826,10 +851,10 @@ chk_add_nr()
 		fi
 
 		echo -n " - ack   "
-		count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMismatchPortAckRx |
-			awk '{print $2}'`
-		[ -z "$count" ] && count=0
-		if [ "$count" != "$mis_ack_nr" ]; then
+		count=$(get_counter ${ns1} "MPTcpExtMismatchPortAckRx")
+		if [ -z "$count" ]; then
+			echo "[skip]"
+		elif [ "$count" != "$mis_ack_nr" ]; then
 			echo "[fail] got $count JOIN[s] ack with a mismatched \
 				port-number expected $mis_ack_nr"
 			ret=1
@@ -868,9 +893,10 @@ chk_rm_nr()
 	fi
 
 	printf "%-39s %s" " " "rm "
-	count=`ip netns exec $addr_ns nstat -as | grep MPTcpExtRmAddr | awk '{print $2}'`
-	[ -z "$count" ] && count=0
-	if [ "$count" != "$rm_addr_nr" ]; then
+	count=$(get_counter ${addr_ns} "MPTcpExtRmAddr")
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif [ "$count" != "$rm_addr_nr" ]; then
 		echo "[fail] got $count RM_ADDR[s] expected $rm_addr_nr"
 		ret=1
 		dump_stats=1
@@ -879,9 +905,10 @@ chk_rm_nr()
 	fi
 
 	echo -n " - sf    "
-	count=`ip netns exec $subflow_ns nstat -as | grep MPTcpExtRmSubflow | awk '{print $2}'`
-	[ -z "$count" ] && count=0
-	if [ "$count" != "$rm_subflow_nr" ]; then
+	count=$(get_counter ${subflow_ns} "MPTcpExtRmSubflow")
+	if [ -z "$count" ]; then
+		echo "[skip]"
+	elif [ "$count" != "$rm_subflow_nr" ]; then
 		echo "[fail] got $count RM_SUBFLOW[s] expected $rm_subflow_nr"
 		ret=1
 		dump_stats=1
@@ -905,9 +932,10 @@ chk_prio_nr()
 	local dump_stats
 
 	printf "%-39s %s" " " "ptx"
-	count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPPrioTx | awk '{print $2}'`
-	[ -z "$count" ] && count=0
-	if [ "$count" != "$mp_prio_nr_tx" ]; then
+	count=$(get_counter ${ns1} "MPTcpExtMPPrioTx")
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif [ "$count" != "$mp_prio_nr_tx" ]; then
 		echo "[fail] got $count MP_PRIO[s] TX expected $mp_prio_nr_tx"
 		ret=1
 		dump_stats=1
@@ -916,9 +944,10 @@ chk_prio_nr()
 	fi
 
 	echo -n " - prx   "
-	count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPPrioRx | awk '{print $2}'`
-	[ -z "$count" ] && count=0
-	if [ "$count" != "$mp_prio_nr_rx" ]; then
+	count=$(get_counter ${ns1} "MPTcpExtMPPrioRx")
+	if [ -z "$count" ]; then
+		echo "[skip]"
+	elif [ "$count" != "$mp_prio_nr_rx" ]; then
 		echo "[fail] got $count MP_PRIO[s] RX expected $mp_prio_nr_rx"
 		ret=1
 		dump_stats=1