[PATCH net v2] selftests: net: amt: wait longer for connection before sending packets

[PATCH net v2] selftests: net: amt: wait longer for connection before sending packets

[Taehee Yoo]

Both send_mcast4() and send_mcast6() use sleep 2 to wait for the tunnel
connection between the gateway and the relay, and for the listener
socket to be created in the LISTENER namespace.

However, tests sometimes fail because packets are sent before the
connection is fully established.

Increase the waiting time to make the tests more reliable, and use
wait_local_port_listen() to explicitly wait for the listener socket.

Fixes: c08e8baea78e ("selftests: add amt interface selftest script")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---

v2:
 - Add wait_local_port_listen() to both send_mcast4() and send_mcast6()

 tools/testing/selftests/net/amt.sh | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/net/amt.sh b/tools/testing/selftests/net/amt.sh
index 3ef209cacb8e..663744305e52 100755
--- a/tools/testing/selftests/net/amt.sh
+++ b/tools/testing/selftests/net/amt.sh
@@ -73,6 +73,8 @@
 #       +------------------------+
 #==============================================================================
 
+source lib.sh
+
 readonly LISTENER=$(mktemp -u listener-XXXXXXXX)
 readonly GATEWAY=$(mktemp -u gateway-XXXXXXXX)
 readonly RELAY=$(mktemp -u relay-XXXXXXXX)
@@ -246,14 +248,15 @@ test_ipv6_forward()
 
 send_mcast4()
 {
-	sleep 2
+	sleep 5
+	wait_local_port_listen ${LISTENER} 4000 udp
 	ip netns exec "${SOURCE}" bash -c \
 		'printf "%s %128s" 172.17.0.2 | nc -w 1 -u 239.0.0.1 4000' &
 }
 
 send_mcast6()
 {
-	sleep 2
+	wait_local_port_listen ${LISTENER} 6000 udp
 	ip netns exec "${SOURCE}" bash -c \
 		'printf "%s %128s" 2001:db8:3::2 | nc -w 1 -u ff0e::5:6 6000' &
 }
-- 
2.43.0

Re: [PATCH net v2] selftests: net: amt: wait longer for connection before sending packets

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Tue, 20 Jan 2026 13:39:30 +0000 you wrote:
> Both send_mcast4() and send_mcast6() use sleep 2 to wait for the tunnel
> connection between the gateway and the relay, and for the listener
> socket to be created in the LISTENER namespace.
> 
> However, tests sometimes fail because packets are sent before the
> connection is fully established.
> 
> [...]

Here is the summary with links:
  - [net,v2] selftests: net: amt: wait longer for connection before sending packets
    https://git.kernel.org/netdev/net/c/04708606fd7b

You are awesome, thank you!
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