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

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

[Taehee Yoo]

There is a sleep 2 in send_mcast4() to wait for the connection to be
established between the gateway and the relay.

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

So, increase the waiting time to make the tests more reliable.

Fixes: c08e8baea78e ("selftests: add amt interface selftest script")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---
 tools/testing/selftests/net/amt.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/amt.sh b/tools/testing/selftests/net/amt.sh
index 3ef209cacb8e..fe2497d9caff 100755
--- a/tools/testing/selftests/net/amt.sh
+++ b/tools/testing/selftests/net/amt.sh
@@ -246,7 +246,7 @@ test_ipv6_forward()
 
 send_mcast4()
 {
-	sleep 2
+	sleep 5
 	ip netns exec "${SOURCE}" bash -c \
 		'printf "%s %128s" 172.17.0.2 | nc -w 1 -u 239.0.0.1 4000' &
 }
-- 
2.43.0

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

[Eric Dumazet]

On Sun, Jan 18, 2026 at 4:15 PM Taehee Yoo <ap420073@gmail.com> wrote:
>
> There is a sleep 2 in send_mcast4() to wait for the connection to be
> established between the gateway and the relay.
>
> However, some tests fail because packets are sometimes sent before the
> connection is fully established.
>
> So, increase the waiting time to make the tests more reliable.
>
> Fixes: c08e8baea78e ("selftests: add amt interface selftest script")
> Signed-off-by: Taehee Yoo <ap420073@gmail.com>
> ---
>  tools/testing/selftests/net/amt.sh | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/net/amt.sh b/tools/testing/selftests/net/amt.sh
> index 3ef209cacb8e..fe2497d9caff 100755
> --- a/tools/testing/selftests/net/amt.sh
> +++ b/tools/testing/selftests/net/amt.sh
> @@ -246,7 +246,7 @@ test_ipv6_forward()
>
>  send_mcast4()
>  {
> -       sleep 2
> +       sleep 5

1) Have you considered using wait_local_port_listen instead ?

2) What about send_mcast6() ?

>         ip netns exec "${SOURCE}" bash -c \
>                 'printf "%s %128s" 172.17.0.2 | nc -w 1 -u 239.0.0.1 4000' &
>  }
> --
> 2.43.0
>

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

[Taehee Yoo]

On Mon, Jan 19, 2026 at 12:38 AM Eric Dumazet <edumazet@google.com> wrote:
>

Hi Eric,
Thanks a lot for the review!

> On Sun, Jan 18, 2026 at 4:15 PM Taehee Yoo <ap420073@gmail.com> wrote:
> >
> > There is a sleep 2 in send_mcast4() to wait for the connection to be
> > established between the gateway and the relay.
> >
> > However, some tests fail because packets are sometimes sent before the
> > connection is fully established.
> >
> > So, increase the waiting time to make the tests more reliable.
> >
> > Fixes: c08e8baea78e ("selftests: add amt interface selftest script")
> > Signed-off-by: Taehee Yoo <ap420073@gmail.com>
> > ---
> >  tools/testing/selftests/net/amt.sh | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/tools/testing/selftests/net/amt.sh b/tools/testing/selftests/net/amt.sh
> > index 3ef209cacb8e..fe2497d9caff 100755
> > --- a/tools/testing/selftests/net/amt.sh
> > +++ b/tools/testing/selftests/net/amt.sh
> > @@ -246,7 +246,7 @@ test_ipv6_forward()
> >
> >  send_mcast4()
> >  {
> > -       sleep 2
> > +       sleep 5
>
> 1) Have you considered using wait_local_port_listen instead ?
>
> 2) What about send_mcast6() ?
>

Thanks, I've testing using use wait_local_port_listen instead of sleep,
it's working very well.
So, I will add the wait_local_port_listen() to send_mcast4() and replace
sleep with wait_local_port_listen in the send_mcast6() in the v2.
The sleep in send_mcast4() is still needed because of waiting for
establishment of amt tunnel.

Thanks a lot!
Taehee Yoo

> >         ip netns exec "${SOURCE}" bash -c \
> >                 'printf "%s %128s" 172.17.0.2 | nc -w 1 -u 239.0.0.1 4000' &
> >  }
> > --
> > 2.43.0
> >