Re: [PATCH bpf-next] tools/testing/selftests/bpf/test_tc_tunnel.sh: Fix wait for server bind

[Stanislav Fomichev <stfomichev@gmail.com>]

On 12/02, Marco Leogrande wrote:
> Commit f803bcf9208a ("selftests/bpf: Prevent client connect before
> server bind in test_tc_tunnel.sh") added code that waits for the
> netcat server to start before the netcat client attempts to connect to
> it. However, not all calls to 'server_listen' were guarded.
> 
> This patch adds the existing 'wait_for_port' guard after the remaining
> call to 'server_listen'.
> 
> Fixes: f803bcf9208a ("selftests/bpf: Prevent client connect before server bind in test_tc_tunnel.sh")
> Signed-off-by: Marco Leogrande <leogrande@google.com>
> ---
>  tools/testing/selftests/bpf/test_tc_tunnel.sh | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/tools/testing/selftests/bpf/test_tc_tunnel.sh b/tools/testing/selftests/bpf/test_tc_tunnel.sh
> index 7989ec6084545..cb55a908bb0d7 100755
> --- a/tools/testing/selftests/bpf/test_tc_tunnel.sh
> +++ b/tools/testing/selftests/bpf/test_tc_tunnel.sh
> @@ -305,6 +305,7 @@ else
>  	client_connect
>  	verify_data
>  	server_listen
> +	wait_for_port ${port} ${netcat_opt}
>  fi
>  
>  # serverside, use BPF for decap
> -- 
> 2.47.0.338.g60cca15819-goog
> 

Do you see this failing in your CI or in the BPF CI? It seems ok
to add wait_for_port here, but the likelihood of the issue seems
minuscule. There is a bunch of ip/tc/etc calls between this
server_listen and the next client_connect (and I'd be surprised to hear
that netcat is still not listening by the time we reach next
client_connect).