These new helpers are easier to read than the long and multi lines
commands. Plus it will ease the addition of new features related to that
in the next commits.

No behavioural changes intended.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 tools/testing/selftests/net/mptcp/mptcp_connect.sh | 12 ++++--------
 tools/testing/selftests/net/mptcp/mptcp_join.sh    | 12 ++++--------
 tools/testing/selftests/net/mptcp/mptcp_lib.sh     | 14 ++++++++++++++
 tools/testing/selftests/net/mptcp/mptcp_sockopt.sh | 12 ++++--------
 tools/testing/selftests/net/mptcp/simult_flows.sh  | 12 ++++--------
 5 files changed, 30 insertions(+), 32 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.sh b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
index 9b7b93f8eb0c..e1f34508490a 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_connect.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
@@ -384,11 +384,9 @@ do_transfer()
 		sleep 1
 	fi
 
-	NSTAT_HISTORY=/tmp/${listener_ns}.nstat ip netns exec ${listener_ns} \
-		nstat -n
+	mptcp_lib_nstat_init "${listener_ns}"
 	if [ ${listener_ns} != ${connector_ns} ]; then
-		NSTAT_HISTORY=/tmp/${connector_ns}.nstat ip netns exec ${connector_ns} \
-			nstat -n
+		mptcp_lib_nstat_init "${connector_ns}"
 	fi
 
 	local stat_synrx_last_l
@@ -436,11 +434,9 @@ do_transfer()
 		kill ${cappid_connector}
 	fi
 
-	NSTAT_HISTORY=/tmp/${listener_ns}.nstat ip netns exec ${listener_ns} \
-		nstat | grep Tcp > /tmp/${listener_ns}.out
+	mptcp_lib_nstat_get "${listener_ns}"
 	if [ ${listener_ns} != ${connector_ns} ]; then
-		NSTAT_HISTORY=/tmp/${connector_ns}.nstat ip netns exec ${connector_ns} \
-			nstat | grep Tcp > /tmp/${connector_ns}.out
+		mptcp_lib_nstat_get "${connector_ns}"
 	fi
 
 	local duration
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index 495b14baccba..ee24adbcfb0c 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -1000,10 +1000,8 @@ do_transfer()
 
 	cond_start_capture ${listener_ns}
 
-	NSTAT_HISTORY=/tmp/${listener_ns}.nstat ip netns exec ${listener_ns} \
-		nstat -n
-	NSTAT_HISTORY=/tmp/${connector_ns}.nstat ip netns exec ${connector_ns} \
-		nstat -n
+	mptcp_lib_nstat_init "${listener_ns}"
+	mptcp_lib_nstat_init "${connector_ns}"
 
 	local extra_args
 	if [ $speed = "fast" ]; then
@@ -1085,10 +1083,8 @@ do_transfer()
 
 	cond_stop_capture
 
-	NSTAT_HISTORY=/tmp/${listener_ns}.nstat ip netns exec ${listener_ns} \
-		nstat | grep Tcp > /tmp/${listener_ns}.out
-	NSTAT_HISTORY=/tmp/${connector_ns}.nstat ip netns exec ${connector_ns} \
-		nstat | grep Tcp > /tmp/${connector_ns}.out
+	mptcp_lib_nstat_get "${listener_ns}"
+	mptcp_lib_nstat_get "${connector_ns}"
 
 	if [ ${rets} -ne 0 ] || [ ${retc} -ne 0 ]; then
 		fail_test "client exit code $retc, server $rets"
diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
index d62e653d48b0..d03aa817ac27 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
@@ -355,6 +355,20 @@ mptcp_lib_is_v6() {
 	[ -z "${1##*:*}" ]
 }
 
+mptcp_lib_nstat_init() {
+	local ns="${1}"
+
+	NSTAT_HISTORY="/tmp/${ns}.nstat" ip netns exec "${ns}" nstat -n
+}
+
+mptcp_lib_nstat_get() {
+	local ns="${1}"
+
+	# filter out non-*TCP stats
+	NSTAT_HISTORY="/tmp/${ns}.nstat" ip netns exec "${ns}" nstat |
+		grep Tcp > "/tmp/${ns}.out"
+}
+
 # $1: ns, $2: MIB counter
 mptcp_lib_get_counter() {
 	local ns="${1}"
diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh b/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh
index f01989be6e9b..343615908558 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.sh
@@ -169,10 +169,8 @@ do_transfer()
 		cmsg+=",TCPINQ"
 	fi
 
-	NSTAT_HISTORY=/tmp/${listener_ns}.nstat ip netns exec ${listener_ns} \
-		nstat -n
-	NSTAT_HISTORY=/tmp/${connector_ns}.nstat ip netns exec ${connector_ns} \
-		nstat -n
+	mptcp_lib_nstat_init "${listener_ns}"
+	mptcp_lib_nstat_init "${connector_ns}"
 
 	timeout ${timeout_test} \
 		ip netns exec ${listener_ns} \
@@ -194,10 +192,8 @@ do_transfer()
 	wait $spid
 	local rets=$?
 
-	NSTAT_HISTORY=/tmp/${listener_ns}.nstat ip netns exec ${listener_ns} \
-		nstat | grep Tcp > /tmp/${listener_ns}.out
-	NSTAT_HISTORY=/tmp/${connector_ns}.nstat ip netns exec ${connector_ns} \
-		nstat | grep Tcp > /tmp/${connector_ns}.out
+	mptcp_lib_nstat_get "${listener_ns}"
+	mptcp_lib_nstat_get "${connector_ns}"
 
 	print_title "Transfer ${ip:2}"
 	if [ ${rets} -ne 0 ] || [ ${retc} -ne 0 ]; then
diff --git a/tools/testing/selftests/net/mptcp/simult_flows.sh b/tools/testing/selftests/net/mptcp/simult_flows.sh
index 1903e8e84a31..fbd1685d1adc 100755
--- a/tools/testing/selftests/net/mptcp/simult_flows.sh
+++ b/tools/testing/selftests/net/mptcp/simult_flows.sh
@@ -155,10 +155,8 @@ do_transfer()
 		sleep 1
 	fi
 
-	NSTAT_HISTORY=/tmp/${ns3}.nstat ip netns exec ${ns3} \
-		nstat -n
-	NSTAT_HISTORY=/tmp/${ns1}.nstat ip netns exec ${ns1} \
-		nstat -n
+	mptcp_lib_nstat_init "${ns3}"
+	mptcp_lib_nstat_init "${ns1}"
 
 	timeout ${timeout_test} \
 		ip netns exec ${ns3} \
@@ -185,10 +183,8 @@ do_transfer()
 		kill ${cappid_connector}
 	fi
 
-	NSTAT_HISTORY=/tmp/${ns3}.nstat ip netns exec ${ns3} \
-		nstat | grep Tcp > /tmp/${ns3}.out
-	NSTAT_HISTORY=/tmp/${ns1}.nstat ip netns exec ${ns1} \
-		nstat | grep Tcp > /tmp/${ns1}.out
+	mptcp_lib_nstat_get "${ns3}"
+	mptcp_lib_nstat_get "${ns1}"
 
 	cmp $sin $cout > /dev/null 2>&1
 	local cmps=$?

-- 
2.51.0