[PATCH net] selftests: net: avoid waiting for server in amt.sh forever when it fails.

[Taehee Yoo <ap420073@gmail.com>]

In the forwarding testcase, it opens a server and a client with the nc.
The server receives the correct message from NC, it prints OK.
The server prints FAIL if it receives the wrong message from the client.

But If the server can't receive any message, it will not close so
the amt.sh waits forever.
There are several reasons.
1. crash of smcrouted.
2. Send a message from the client to the server before the server is up.

To avoid this problem, the server waits only for 10 seconds.
The client sends messages for 10 seconds.
If the server is successfully closed, it kills the client.

Fixes: c08e8baea78e ("selftests: add amt interface selftest script")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---
 tools/testing/selftests/net/amt.sh | 63 +++++++++++++++++++-----------
 1 file changed, 40 insertions(+), 23 deletions(-)

diff --git a/tools/testing/selftests/net/amt.sh b/tools/testing/selftests/net/amt.sh
index 75528788cb95..16641d3dccce 100755
--- a/tools/testing/selftests/net/amt.sh
+++ b/tools/testing/selftests/net/amt.sh
@@ -77,6 +77,7 @@ readonly LISTENER=$(mktemp -u listener-XXXXXXXX)
 readonly GATEWAY=$(mktemp -u gateway-XXXXXXXX)
 readonly RELAY=$(mktemp -u relay-XXXXXXXX)
 readonly SOURCE=$(mktemp -u source-XXXXXXXX)
+readonly RESULT=$(mktemp -p /tmp amt-XXXXXXXX)
 ERR=4
 err=0
 
@@ -85,6 +86,10 @@ exit_cleanup()
 	for ns in "$@"; do
 		ip netns delete "${ns}" 2>/dev/null || true
 	done
+	rm $RESULT
+	smcpid=$(< $SMCROUTEDIR/amt.pid)
+	kill $smcpid
+	rm -rf $SMCROUTEDIR
 
 	exit $ERR
 }
@@ -167,7 +172,9 @@ setup_iptables()
 
 setup_mcast_routing()
 {
-	ip netns exec "${RELAY}" smcrouted
+	SMCROUTEDIR="$(mktemp -d)"
+
+	ip netns exec "${RELAY}" smcrouted -P $SMCROUTEDIR/amt.pid
 	ip netns exec "${RELAY}" smcroutectl a relay_src \
 		172.17.0.2 239.0.0.1 amtr
 	ip netns exec "${RELAY}" smcroutectl a relay_src \
@@ -210,40 +217,52 @@ check_features()
 
 test_ipv4_forward()
 {
-	RESULT4=$(ip netns exec "${LISTENER}" nc -w 1 -l -u 239.0.0.1 4000)
+	echo "" > $RESULT
+	bash -c "$(ip netns exec "${LISTENER}" \
+		timeout 10s nc -w 1 -l -u 239.0.0.1 4000 > $RESULT)"
+	RESULT4=$(< $RESULT)
 	if [ "$RESULT4" == "172.17.0.2" ]; then
 		printf "TEST: %-60s  [ OK ]\n" "IPv4 amt multicast forwarding"
-		exit 0
 	else
 		printf "TEST: %-60s  [FAIL]\n" "IPv4 amt multicast forwarding"
-		exit 1
 	fi
+
 }
 
 test_ipv6_forward()
 {
-	RESULT6=$(ip netns exec "${LISTENER}" nc -w 1 -l -u ff0e::5:6 6000)
+	echo "" > $RESULT
+	bash -c "$(ip netns exec "${LISTENER}" \
+		timeout 10s nc -w 1 -l -u ff0e::5:6 6000 > $RESULT)"
+	RESULT6=$(< $RESULT)
 	if [ "$RESULT6" == "2001:db8:3::2" ]; then
 		printf "TEST: %-60s  [ OK ]\n" "IPv6 amt multicast forwarding"
-		exit 0
 	else
 		printf "TEST: %-60s  [FAIL]\n" "IPv6 amt multicast forwarding"
-		exit 1
 	fi
+
 }
 
 send_mcast4()
 {
 	sleep 2
-	ip netns exec "${SOURCE}" bash -c \
-		'echo 172.17.0.2 | nc -w 1 -u 239.0.0.1 4000' &
+	for n in {0..10}; do
+		ip netns exec "${SOURCE}" bash -c \
+			'echo 172.17.0.2 | nc -w 1 -u 239.0.0.1 4000'
+		sleep 1
+	done
+
 }
 
 send_mcast6()
 {
 	sleep 2
-	ip netns exec "${SOURCE}" bash -c \
-		'echo 2001:db8:3::2 | nc -w 1 -u ff0e::5:6 6000' &
+	for n in {0..10}; do
+		ip netns exec "${SOURCE}" bash -c \
+			'echo 2001:db8:3::2 | nc -w 1 -u ff0e::5:6 6000'
+		sleep 1
+	done
+
 }
 
 check_features
@@ -259,19 +278,17 @@ setup_iptables
 setup_mcast_routing
 test_remote_ip
 test_ipv4_forward &
-pid=$!
-send_mcast4
-wait $pid || err=$?
-if [ $err -eq 1 ]; then
-	ERR=1
-fi
+spid=$!
+send_mcast4 &
+cpid=$!
+wait $spid
+kill $cpid
 test_ipv6_forward &
-pid=$!
-send_mcast6
-wait $pid || err=$?
-if [ $err -eq 1 ]; then
-	ERR=1
-fi
+spid=$!
+send_mcast6 &
+cpid=$!
+wait $spid
+kill $cpid
 send_mcast_torture4
 printf "TEST: %-60s  [ OK ]\n" "IPv4 amt traffic forwarding torture"
 send_mcast_torture6
-- 
2.34.1