selftests: mptcp: add print_title in mptcp_lib

This patch adds a new variable MPTCP_LIB_TEST_FORMAT as the test title
printing format. Also add a helper mptcp_lib_print_title() to use this
format to print the test title with test counters. They are used in
mptcp_join.sh first.

Each MPTCP selftest is having subtests, and it helps to give them a
number to quickly identify them. This can be managed by mptcp_lib.sh,
reusing what has been done here. The following commit will use these
new helpers in the other tests.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20240308-upstream-net-next-20240308-selftests-mptcp-unification-v1-6-4f42c347b653@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Geliang Tang

tools/testing/selftests/net/mptcp/mptcp_join.sh

@@ -48,6 +48,7 @@ declare -A all_tests
 declare -a only_tests_ids
 declare -a only_tests_names
 declare -A failed_tests
+MPTCP_LIB_TEST_FORMAT="%03u %s\n"
 TEST_NAME=""
 nr_blank=6
 
@@ -169,11 +170,6 @@ cleanup()
 	cleanup_partial
 }
 
-print_title()
-{
-	printf "%03u %s\n" "${MPTCP_LIB_TEST_COUNTER}" "${TEST_NAME}"
-}
-
 print_check()
 {
 	printf "%-${nr_blank}s%-36s" " " "${*}"
@@ -232,7 +228,7 @@ skip_test()
 
 	local i
 	for i in "${only_tests_ids[@]}"; do
-		if [ "${MPTCP_LIB_TEST_COUNTER}" -eq "${i}" ]; then
+		if [ "$((MPTCP_LIB_TEST_COUNTER+1))" -eq "${i}" ]; then
 			return 1
 		fi
 	done
@@ -267,14 +263,13 @@ reset()
 
 	TEST_NAME="${1}"
 
-	MPTCP_LIB_TEST_COUNTER=$((MPTCP_LIB_TEST_COUNTER+1))
-
 	if skip_test; then
+		MPTCP_LIB_TEST_COUNTER=$((MPTCP_LIB_TEST_COUNTER+1))
 		last_test_ignored=1
 		return 1
 	fi
 
-	print_title
+	mptcp_lib_print_title "${TEST_NAME}"
 
 	if [ "${init}" != "1" ]; then
 		init

tools/testing/selftests/net/mptcp/mptcp_lib.sh

@@ -10,8 +10,8 @@ readonly KSFT_TEST="${MPTCP_LIB_KSFT_TEST:-$(basename "${0}" .sh)}"
 
 MPTCP_LIB_SUBTESTS=()
 MPTCP_LIB_SUBTESTS_DUPLICATED=0
-# shellcheck disable=SC2034 # unused at this moment
 MPTCP_LIB_TEST_COUNTER=0
+MPTCP_LIB_TEST_FORMAT="%02u %-50s"
 
 # only if supported (or forced) and not disabled, see no-color.org
 if { [ -t 1 ] || [ "${SELFTESTS_MPTCP_LIB_COLOR_FORCE:-}" = "1" ]; } &&
@@ -412,3 +412,11 @@ mptcp_lib_events() {
 	ip netns exec "${ns}" ./pm_nl_ctl events >> "${evts}" 2>&1 &
 	pid=$!
 }
+
+mptcp_lib_print_title() {
+	: "${MPTCP_LIB_TEST_COUNTER:?}"
+	: "${MPTCP_LIB_TEST_FORMAT:?}"
+
+	# shellcheck disable=SC2059 # the format is in a variable
+	printf "${MPTCP_LIB_TEST_FORMAT}" "$((++MPTCP_LIB_TEST_COUNTER))" "${*}"
+}