selftests: mptcp: export ip_mptcp to mptcp_lib

This patch exports ip_mptcp into mptcp_lib.sh as a public variable,
named MPTCP_LIB_IP_MPTCP. Add a helper mptcp_lib_set_ip_mptcp() to set
it, and a helper mptcp_lib_is_ip_mptcp() to test whether it is set. Use
these two helpers in mptcp_join.sh.

This patch is prepared for coming commits.
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>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -31,7 +31,6 @@ timeout_poll=30
 timeout_test=$((timeout_poll * 2 + 1))
 capture=false
 checksum=false
-ip_mptcp=0
 check_invert=0
 validate_checksum=false
 init=0
@@ -610,7 +609,7 @@ pm_nl_set_limits()
 	local addrs=$2
 	local subflows=$3
 
-	if [ $ip_mptcp -eq 1 ]; then
+	if mptcp_lib_is_ip_mptcp; then
 		ip -n $ns mptcp limits set add_addr_accepted $addrs subflows $subflows
 	else
 		ip netns exec $ns ./pm_nl_ctl limits $addrs $subflows
@@ -650,7 +649,7 @@ pm_nl_add_endpoint()
 		nr=$((nr + 1))
 	done
 
-	if [ $ip_mptcp -eq 1 ]; then
+	if mptcp_lib_is_ip_mptcp; then
 		ip -n $ns mptcp endpoint add $addr ${_flags//","/" "} $dev $id $port
 	else
 		ip netns exec $ns ./pm_nl_ctl add $addr $flags $dev $id $port
@@ -663,7 +662,7 @@ pm_nl_del_endpoint()
 	local id=$2
 	local addr=$3
 
-	if [ $ip_mptcp -eq 1 ]; then
+	if mptcp_lib_is_ip_mptcp; then
 		[ $id -ne 0 ] && addr=''
 		ip -n $ns mptcp endpoint delete id $id $addr
 	else
@@ -675,7 +674,7 @@ pm_nl_flush_endpoint()
 {
 	local ns=$1
 
-	if [ $ip_mptcp -eq 1 ]; then
+	if mptcp_lib_is_ip_mptcp; then
 		ip -n $ns mptcp endpoint flush
 	else
 		ip netns exec $ns ./pm_nl_ctl flush
@@ -686,7 +685,7 @@ pm_nl_show_endpoints()
 {
 	local ns=$1
 
-	if [ $ip_mptcp -eq 1 ]; then
+	if mptcp_lib_is_ip_mptcp; then
 		ip -n $ns mptcp endpoint show
 	else
 		ip netns exec $ns ./pm_nl_ctl dump
@@ -699,7 +698,7 @@ pm_nl_change_endpoint()
 	local id=$2
 	local flags=$3
 
-	if [ $ip_mptcp -eq 1 ]; then
+	if mptcp_lib_is_ip_mptcp; then
 		ip -n $ns mptcp endpoint change id $id ${flags//","/" "}
 	else
 		ip netns exec $ns ./pm_nl_ctl set id $id flags $flags
@@ -749,7 +748,7 @@ pm_nl_check_endpoint()
 		return
 	fi
 
-	if [ $ip_mptcp -eq 1 ]; then
+	if mptcp_lib_is_ip_mptcp; then
 		# get line and trim trailing whitespace
 		line=$(ip -n $ns mptcp endpoint show $id)
 		line="${line% }"
@@ -3702,7 +3701,7 @@ while getopts "${all_tests_args}cCih" opt; do
 			checksum=true
 			;;
 		i)
-			ip_mptcp=1
+			mptcp_lib_set_ip_mptcp
 			;;
 		h)
 			usage

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

@@ -23,6 +23,7 @@ MPTCP_LIB_SUBTESTS=()
 MPTCP_LIB_SUBTESTS_DUPLICATED=0
 MPTCP_LIB_TEST_COUNTER=0
 MPTCP_LIB_TEST_FORMAT="%02u %-50s"
+MPTCP_LIB_IP_MPTCP=0
 
 # only if supported (or forced) and not disabled, see no-color.org
 if { [ -t 1 ] || [ "${SELFTESTS_MPTCP_LIB_COLOR_FORCE:-}" = "1" ]; } &&
@@ -511,3 +512,11 @@ mptcp_lib_verify_listener_events() {
 	mptcp_lib_check_expected "type" "family" "saddr" "sport" || rc="${?}"
 	return "${rc}"
 }
+
+mptcp_lib_set_ip_mptcp() {
+	MPTCP_LIB_IP_MPTCP=1
+}
+
+mptcp_lib_is_ip_mptcp() {
+	[ "${MPTCP_LIB_IP_MPTCP}" = "1" ]
+}