[PATCH net 04/17] selftests: mptcp: join: skip check if MIB counter not supported

[Matthieu Baerts <matthieu.baerts@tessares.net>]

Selftests are supposed to run on any kernels, including the old ones not
supporting all MPTCP features.

One of them is the MPTCP MIB counters introduced in commit fc518953bc9c
("mptcp: add and use MIB counter infrastructure") and more later. The
MPTCP Join selftest heavily relies on these counters.

If a counter is not supported by the kernel, it is not displayed when
using 'nstat -z'. We can then detect that and skip the verification. A
new helper (get_counter()) has been added to do the required checks and
return an error if the counter is not available.

Note that if we expect to have these features available and if
SELFTESTS_MPTCP_LIB_EXPECT_ALL_FEATURES env var is set to 1, the tests
will be marked as failed instead of skipped.

This new helper also makes sure we get the exact counter we want to
avoid issues we had in the past, e.g. with MPTcpExtRmAddr and
MPTcpExtRmAddrDrop sharing the same prefix. While at it, we uniform the
way we fetch a MIB counter.

Note for the backports: we rarely change these modified blocks so if
there is are conflicts, it is very likely because a counter is not used
in the older kernels and we don't need that chunk.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/368
Fixes: b08fbf241064 ("selftests: add test-cases for MPTCP MP_JOIN")
Cc: stable@vger.kernel.org
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
---
 tools/testing/selftests/net/mptcp/mptcp_join.sh | 230 +++++++++++++-----------
 1 file changed, 130 insertions(+), 100 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index a63aed145393..276396cbe60c 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -500,11 +500,25 @@ wait_local_port_listen()
 	done
 }
 
+# $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}"
+}
+
 rm_addr_count()
 {
-	local ns=${1}
-
-	ip netns exec ${ns} nstat -as | grep MPTcpExtRmAddr | awk '{print $2}'
+	get_counter "${1}" "MPTcpExtRmAddr"
 }
 
 # $1: ns, $2: old rm_addr counter in $ns
@@ -527,11 +541,11 @@ wait_mpj()
 	local ns="${1}"
 	local cnt old_cnt
 
-	old_cnt=$(ip netns exec ${ns} nstat -as | grep MPJoinAckRx | awk '{print $2}')
+	old_cnt=$(get_counter ${ns} "MPTcpExtMPJoinAckRx")
 
 	local i
 	for i in $(seq 10); do
-		cnt=$(ip netns exec ${ns} nstat -as | grep MPJoinAckRx | awk '{print $2}')
+		cnt=$(get_counter ${ns} "MPTcpExtMPJoinAckRx")
 		[ "$cnt" = "${old_cnt}" ] || break
 		sleep 0.1
 	done
@@ -1190,12 +1204,13 @@ chk_csum_nr()
 	fi
 
 	printf "%-${nr_blank}s %s" " " "sum"
-	count=$(ip netns exec $ns1 nstat -as | grep MPTcpExtDataCsumErr | awk '{print $2}')
-	[ -z "$count" ] && count=0
+	count=$(get_counter ${ns1} "MPTcpExtDataCsumErr")
 	if [ "$count" != "$csum_ns1" ]; then
 		extra_msg="$extra_msg ns1=$count"
 	fi
-	if { [ "$count" != $csum_ns1 ] && [ $allow_multi_errors_ns1 -eq 0 ]; } ||
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif { [ "$count" != $csum_ns1 ] && [ $allow_multi_errors_ns1 -eq 0 ]; } ||
 	   { [ "$count" -lt $csum_ns1 ] && [ $allow_multi_errors_ns1 -eq 1 ]; }; then
 		echo "[fail] got $count data checksum error[s] expected $csum_ns1"
 		fail_test
@@ -1204,12 +1219,13 @@ chk_csum_nr()
 		echo -n "[ ok ]"
 	fi
 	echo -n " - csum  "
-	count=$(ip netns exec $ns2 nstat -as | grep MPTcpExtDataCsumErr | awk '{print $2}')
-	[ -z "$count" ] && count=0
+	count=$(get_counter ${ns2} "MPTcpExtDataCsumErr")
 	if [ "$count" != "$csum_ns2" ]; then
 		extra_msg="$extra_msg ns2=$count"
 	fi
-	if { [ "$count" != $csum_ns2 ] && [ $allow_multi_errors_ns2 -eq 0 ]; } ||
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif { [ "$count" != $csum_ns2 ] && [ $allow_multi_errors_ns2 -eq 0 ]; } ||
 	   { [ "$count" -lt $csum_ns2 ] && [ $allow_multi_errors_ns2 -eq 1 ]; }; then
 		echo "[fail] got $count data checksum error[s] expected $csum_ns2"
 		fail_test
@@ -1251,12 +1267,13 @@ chk_fail_nr()
 	fi
 
 	printf "%-${nr_blank}s %s" " " "ftx"
-	count=$(ip netns exec $ns_tx nstat -as | grep MPTcpExtMPFailTx | awk '{print $2}')
-	[ -z "$count" ] && count=0
+	count=$(get_counter ${ns_tx} "MPTcpExtMPFailTx")
 	if [ "$count" != "$fail_tx" ]; then
 		extra_msg="$extra_msg,tx=$count"
 	fi
-	if { [ "$count" != "$fail_tx" ] && [ $allow_tx_lost -eq 0 ]; } ||
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif { [ "$count" != "$fail_tx" ] && [ $allow_tx_lost -eq 0 ]; } ||
 	   { [ "$count" -gt "$fail_tx" ] && [ $allow_tx_lost -eq 1 ]; }; then
 		echo "[fail] got $count MP_FAIL[s] TX expected $fail_tx"
 		fail_test
@@ -1266,12 +1283,13 @@ chk_fail_nr()
 	fi
 
 	echo -n " - failrx"
-	count=$(ip netns exec $ns_rx nstat -as | grep MPTcpExtMPFailRx | awk '{print $2}')
-	[ -z "$count" ] && count=0
+	count=$(get_counter ${ns_rx} "MPTcpExtMPFailRx")
 	if [ "$count" != "$fail_rx" ]; then
 		extra_msg="$extra_msg,rx=$count"
 	fi
-	if { [ "$count" != "$fail_rx" ] && [ $allow_rx_lost -eq 0 ]; } ||
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif { [ "$count" != "$fail_rx" ] && [ $allow_rx_lost -eq 0 ]; } ||
 	   { [ "$count" -gt "$fail_rx" ] && [ $allow_rx_lost -eq 1 ]; }; then
 		echo "[fail] got $count MP_FAIL[s] RX expected $fail_rx"
 		fail_test
@@ -1303,10 +1321,11 @@ chk_fclose_nr()
 	fi
 
 	printf "%-${nr_blank}s %s" " " "ctx"
-	count=$(ip netns exec $ns_tx nstat -as | grep MPTcpExtMPFastcloseTx | awk '{print $2}')
-	[ -z "$count" ] && count=0
-	[ "$count" != "$fclose_tx" ] && extra_msg="$extra_msg,tx=$count"
-	if [ "$count" != "$fclose_tx" ]; then
+	count=$(get_counter ${ns_tx} "MPTcpExtMPFastcloseTx")
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif [ "$count" != "$fclose_tx" ]; then
+		extra_msg="$extra_msg,tx=$count"
 		echo "[fail] got $count MP_FASTCLOSE[s] TX expected $fclose_tx"
 		fail_test
 		dump_stats=1
@@ -1315,10 +1334,11 @@ chk_fclose_nr()
 	fi
 
 	echo -n " - fclzrx"
-	count=$(ip netns exec $ns_rx nstat -as | grep MPTcpExtMPFastcloseRx | awk '{print $2}')
-	[ -z "$count" ] && count=0
-	[ "$count" != "$fclose_rx" ] && extra_msg="$extra_msg,rx=$count"
-	if [ "$count" != "$fclose_rx" ]; then
+	count=$(get_counter ${ns_rx} "MPTcpExtMPFastcloseRx")
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif [ "$count" != "$fclose_rx" ]; then
+		extra_msg="$extra_msg,rx=$count"
 		echo "[fail] got $count MP_FASTCLOSE[s] RX expected $fclose_rx"
 		fail_test
 		dump_stats=1
@@ -1349,9 +1369,10 @@ chk_rst_nr()
 	fi
 
 	printf "%-${nr_blank}s %s" " " "rtx"
-	count=$(ip netns exec $ns_tx nstat -as | grep MPTcpExtMPRstTx | awk '{print $2}')
-	[ -z "$count" ] && count=0
-	if [ $count -lt $rst_tx ]; then
+	count=$(get_counter ${ns_tx} "MPTcpExtMPRstTx")
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif [ $count -lt $rst_tx ]; then
 		echo "[fail] got $count MP_RST[s] TX expected $rst_tx"
 		fail_test
 		dump_stats=1
@@ -1360,9 +1381,10 @@ chk_rst_nr()
 	fi
 
 	echo -n " - rstrx "
-	count=$(ip netns exec $ns_rx nstat -as | grep MPTcpExtMPRstRx | awk '{print $2}')
-	[ -z "$count" ] && count=0
-	if [ "$count" -lt "$rst_rx" ]; then
+	count=$(get_counter ${ns_rx} "MPTcpExtMPRstRx")
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif [ "$count" -lt "$rst_rx" ]; then
 		echo "[fail] got $count MP_RST[s] RX expected $rst_rx"
 		fail_test
 		dump_stats=1
@@ -1383,9 +1405,10 @@ chk_infi_nr()
 	local dump_stats
 
 	printf "%-${nr_blank}s %s" " " "itx"
-	count=$(ip netns exec $ns2 nstat -as | grep InfiniteMapTx | awk '{print $2}')
-	[ -z "$count" ] && count=0
-	if [ "$count" != "$infi_tx" ]; then
+	count=$(get_counter ${ns2} "MPTcpExtInfiniteMapTx")
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif [ "$count" != "$infi_tx" ]; then
 		echo "[fail] got $count infinite map[s] TX expected $infi_tx"
 		fail_test
 		dump_stats=1
@@ -1394,9 +1417,10 @@ chk_infi_nr()
 	fi
 
 	echo -n " - infirx"
-	count=$(ip netns exec $ns1 nstat -as | grep InfiniteMapRx | awk '{print $2}')
-	[ -z "$count" ] && count=0
-	if [ "$count" != "$infi_rx" ]; then
+	count=$(get_counter ${ns1} "MPTcpExtInfiniteMapRx")
+	if [ -z "$count" ]; then
+		echo "[skip]"
+	elif [ "$count" != "$infi_rx" ]; then
 		echo "[fail] got $count infinite map[s] RX expected $infi_rx"
 		fail_test
 		dump_stats=1
@@ -1428,9 +1452,10 @@ chk_join_nr()
 	fi
 
 	printf "%03u %-36s %s" "${TEST_COUNT}" "${title}" "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"
 		fail_test
 		dump_stats=1
@@ -1440,9 +1465,10 @@ 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
@@ -1458,9 +1484,10 @@ 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"
 		fail_test
 		dump_stats=1
@@ -1492,12 +1519,12 @@ chk_stale_nr()
 	local recover_nr
 
 	printf "%-${nr_blank}s %-18s" " " "stale"
-	stale_nr=$(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 $stale_min ] ||
+	stale_nr=$(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 ] && [ $stale_nr -gt $stale_max ]; } ||
 	   [ $((stale_nr - recover_nr)) -ne $stale_delta ]; then
 		echo "[fail] got $stale_nr stale[s] $recover_nr recover[s], " \
@@ -1533,12 +1560,12 @@ chk_add_nr()
 	timeout=$(ip netns exec $ns1 sysctl -n net.mptcp.add_addr_timeout)
 
 	printf "%-${nr_blank}s %s" " " "add"
-	count=$(ip netns exec $ns2 nstat -as MPTcpExtAddAddr | grep MPTcpExtAddAddr | awk '{print $2}')
-	[ -z "$count" ] && count=0
-
+	count=$(get_counter ${ns2} "MPTcpExtAddAddr")
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
 	# if the test configured a short timeout tolerate greater then expected
 	# add addrs options, due to retransmissions
-	if [ "$count" != "$add_nr" ] && { [ "$timeout" -gt 1 ] || [ "$count" -lt "$add_nr" ]; }; then
+	elif [ "$count" != "$add_nr" ] && { [ "$timeout" -gt 1 ] || [ "$count" -lt "$add_nr" ]; }; then
 		echo "[fail] got $count ADD_ADDR[s] expected $add_nr"
 		fail_test
 		dump_stats=1
@@ -1547,9 +1574,10 @@ 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"
 		fail_test
 		dump_stats=1
@@ -1559,9 +1587,10 @@ 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"
 			fail_test
 			dump_stats=1
@@ -1570,10 +1599,10 @@ chk_add_nr()
 		fi
 
 		printf "%-${nr_blank}s %s" " " "syn"
-		count=$(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"
 			fail_test
@@ -1583,10 +1612,10 @@ 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"
 			fail_test
@@ -1596,10 +1625,10 @@ 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"
 			fail_test
@@ -1609,10 +1638,10 @@ chk_add_nr()
 		fi
 
 		printf "%-${nr_blank}s %s" " " "syn"
-		count=$(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"
 			fail_test
@@ -1622,10 +1651,10 @@ 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"
 			fail_test
@@ -1669,9 +1698,10 @@ chk_rm_nr()
 	fi
 
 	printf "%-${nr_blank}s %s" " " "rm "
-	count=$(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"
 		fail_test
 		dump_stats=1
@@ -1680,29 +1710,27 @@ chk_rm_nr()
 	fi
 
 	echo -n " - rmsf  "
-	count=$(ip netns exec $subflow_ns nstat -as | grep MPTcpExtRmSubflow | awk '{print $2}')
-	[ -z "$count" ] && count=0
-	if [ -n "$simult" ]; then
+	count=$(get_counter ${subflow_ns} "MPTcpExtRmSubflow")
+	if [ -z "$count" ]; then
+		echo -n "[skip]"
+	elif [ -n "$simult" ]; then
 		local cnt suffix
 
-		cnt=$(ip netns exec $addr_ns nstat -as | grep MPTcpExtRmSubflow | awk '{print $2}')
+		cnt=$(get_counter ${addr_ns} "MPTcpExtRmSubflow")
 
 		# in case of simult flush, the subflow removal count on each side is
 		# unreliable
-		[ -z "$cnt" ] && cnt=0
 		count=$((count + cnt))
 		[ "$count" != "$rm_subflow_nr" ] && suffix="$count in [$rm_subflow_nr:$((rm_subflow_nr*2))]"
 		if [ $count -ge "$rm_subflow_nr" ] && \
 		   [ "$count" -le "$((rm_subflow_nr *2 ))" ]; then
-			echo "[ ok ] $suffix"
+			echo -n "[ ok ] $suffix"
 		else
 			echo "[fail] got $count RM_SUBFLOW[s] expected in range [$rm_subflow_nr:$((rm_subflow_nr*2))]"
 			fail_test
 			dump_stats=1
 		fi
-		return
-	fi
-	if [ "$count" != "$rm_subflow_nr" ]; then
+	elif [ "$count" != "$rm_subflow_nr" ]; then
 		echo "[fail] got $count RM_SUBFLOW[s] expected $rm_subflow_nr"
 		fail_test
 		dump_stats=1
@@ -1723,9 +1751,10 @@ chk_prio_nr()
 	local dump_stats
 
 	printf "%-${nr_blank}s %s" " " "ptx"
-	count=$(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"
 		fail_test
 		dump_stats=1
@@ -1734,9 +1763,10 @@ 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"
 		fail_test
 		dump_stats=1
@@ -1852,7 +1882,7 @@ wait_attempt_fail()
 	while [ $time -lt $timeout_ms ]; do
 		local cnt
 
-		cnt=$(ip netns exec $ns nstat -as TcpAttemptFails | grep TcpAttemptFails | awk '{print $2}')
+		cnt=$(get_counter ${ns} "TcpAttemptFails")
 
 		[ "$cnt" = 1 ] && return 1
 		time=$((time + 100))

-- 
2.40.1