[PATCH net-next v4 1/2] selftests/bpf: Track test_xdp_features DUT processes

[Bochao Cao via B4 Relay <devnull+bochaolucky.gmail.com@kernel.org>]

From: Bochao Cao <bochaolucky@gmail.com>

Track the DUT process instead of matching processes by name to avoid
interference between concurrent tests. Fix readiness retries under
set -e and clean up the DUT and network state on exit or interruption.

Signed-off-by: Bochao Cao <bochaolucky@gmail.com>
---
 tools/testing/selftests/bpf/test_xdp_features.sh | 88 ++++++++++++++++++------
 1 file changed, 68 insertions(+), 20 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_xdp_features.sh b/tools/testing/selftests/bpf/test_xdp_features.sh
index 0aa71c445..a78e0fb9e 100755
--- a/tools/testing/selftests/bpf/test_xdp_features.sh
+++ b/tools/testing/selftests/bpf/test_xdp_features.sh
@@ -8,6 +8,7 @@ readonly V0_IP6=2001:db8::11
 readonly V1_IP6=2001:db8::1
 
 ret=1
+dut_pid=""
 
 setup() {
 	{
@@ -30,77 +31,124 @@ setup() {
 	} > /dev/null 2>&1
 }
 
+terminate_dut_server() {
+	local pid
+
+	# Use the shell job instead of dut_pid, which may not have been assigned
+	# yet if a signal arrived immediately after the server was started.
+	pid=$(jobs -pr %% 2> /dev/null) || true
+	if [ -z "$pid" ]; then
+		dut_pid=""
+		return
+	fi
+
+	kill -KILL %% 2> /dev/null || true
+	wait "$pid" 2> /dev/null || true
+	dut_pid=""
+}
+
 cleanup() {
-	ip link del v1 2> /dev/null
-	ip netns del ${NS} 2> /dev/null
-	[ "$(pidof xdp_features)" = "" ] || kill $(pidof xdp_features) 2> /dev/null
+	terminate_dut_server
+	ip link del v1 2> /dev/null || true
+	ip netns del "${NS}" 2> /dev/null || true
 }
 
 wait_for_dut_server() {
-	while sleep 1; do
-		ss -tlp | grep -q xdp_features
-		[ $? -eq 0 ] && break
+	local i
+
+	for ((i = 0; i < 10; i++)); do
+		if [ "$(jobs -pr %% 2> /dev/null)" != "$dut_pid" ]; then
+			echo "xdp_features server $dut_pid exited before accepting connections" >&2
+			return 1
+		fi
+
+		if ss -tlp 2> /dev/null | grep -q "pid=$dut_pid,"; then
+			return 0
+		fi
+
+		sleep 1
 	done
+
+	echo "Timed out waiting for xdp_features server $dut_pid" >&2
+	return 1
+}
+
+start_dut_server() {
+	./xdp_features "$@" &
+	dut_pid=$!
+	wait_for_dut_server
+}
+
+reap_dut_server() {
+	local status=0
+
+	wait "$dut_pid" || status=$?
+	dut_pid=""
+	return "$status"
 }
 
 test_xdp_features() {
 	setup
 
 	## XDP_PASS
-	./xdp_features -f XDP_PASS -D $V1_IP6 -T $V0_IP6 v1 &
-	wait_for_dut_server
+	start_dut_server -f XDP_PASS -D $V1_IP6 -T $V0_IP6 v1
 	ip netns exec ${NS} ./xdp_features -t -f XDP_PASS \
 					   -D $V1_IP6 -C $V1_IP6 \
 					   -T $V0_IP6 v0
 	[ $? -ne 0 ] && exit
+	reap_dut_server
 
 	## XDP_DROP
-	./xdp_features -f XDP_DROP -D ::ffff:$V1_IP4 -T ::ffff:$V0_IP4 v1 &
-	wait_for_dut_server
+	start_dut_server -f XDP_DROP -D ::ffff:$V1_IP4 -T ::ffff:$V0_IP4 v1
 	ip netns exec ${NS} ./xdp_features -t -f XDP_DROP \
 					   -D ::ffff:$V1_IP4 \
 					   -C ::ffff:$V1_IP4 \
 					   -T ::ffff:$V0_IP4 v0
 	[ $? -ne 0 ] && exit
+	reap_dut_server
 
 	## XDP_ABORTED
-	./xdp_features -f XDP_ABORTED -D $V1_IP6 -T $V0_IP6 v1 &
-	wait_for_dut_server
+	start_dut_server -f XDP_ABORTED -D $V1_IP6 -T $V0_IP6 v1
 	ip netns exec ${NS} ./xdp_features -t -f XDP_ABORTED \
 					   -D $V1_IP6 -C $V1_IP6 \
 					   -T $V0_IP6 v0
 	[ $? -ne 0 ] && exit
+	reap_dut_server
 
 	## XDP_TX
-	./xdp_features -f XDP_TX -D ::ffff:$V1_IP4 -T ::ffff:$V0_IP4 v1 &
-	wait_for_dut_server
+	start_dut_server -f XDP_TX -D ::ffff:$V1_IP4 -T ::ffff:$V0_IP4 v1
 	ip netns exec ${NS} ./xdp_features -t -f XDP_TX \
 					   -D ::ffff:$V1_IP4 \
 					   -C ::ffff:$V1_IP4 \
 					   -T ::ffff:$V0_IP4 v0
 	[ $? -ne 0 ] && exit
+	reap_dut_server
 
 	## XDP_REDIRECT
-	./xdp_features -f XDP_REDIRECT -D $V1_IP6 -T $V0_IP6 v1 &
-	wait_for_dut_server
+	start_dut_server -f XDP_REDIRECT -D $V1_IP6 -T $V0_IP6 v1
 	ip netns exec ${NS} ./xdp_features -t -f XDP_REDIRECT \
 					   -D $V1_IP6 -C $V1_IP6 \
 					   -T $V0_IP6 v0
 	[ $? -ne 0 ] && exit
+	reap_dut_server
 
 	## XDP_NDO_XMIT
-	./xdp_features -f XDP_NDO_XMIT -D ::ffff:$V1_IP4 -T ::ffff:$V0_IP4 v1 &
-	wait_for_dut_server
+	start_dut_server -f XDP_NDO_XMIT -D ::ffff:$V1_IP4 -T ::ffff:$V0_IP4 v1
 	ip netns exec ${NS} ./xdp_features -t -f XDP_NDO_XMIT \
 					   -D ::ffff:$V1_IP4 \
 					   -C ::ffff:$V1_IP4 \
 					   -T ::ffff:$V0_IP4 v0
 	ret=$?
-	cleanup
+	reap_dut_server
 }
 
 set -e
-trap cleanup 2 3 6 9
+trap cleanup EXIT
+trap 'exit 129' HUP
+trap 'exit 130' INT
+trap 'exit 131' QUIT
+trap 'exit 134' ABRT
+trap 'exit 143' TERM
 
 test_xdp_features
 

-- 
2.43.0