Subject: RE: [PATCH bpf 1/7] selftests/bpf/test_xdp_redirect_multi: use temp netns for testing

From: John Fastabend <[email-masked]>
Date: Wed, 26 Jan 2022 21:34:52 -0800

Hangbin Liu wrote:
> Use temp netns instead of hard code name for testing in case the netns
> already exists.
> 
> Remove the hard code interface index when creating the veth interfaces.
> Because when the system loads some virtual interface modules, e.g. tunnels.
> the ifindex of 2 will be used and the cmd will fail.
> 
> As the netns has not created if checking environment failed. Trap the
> clean up function after checking env.
> 
> Fixes: 8955c1a32987 ("selftests/bpf/xdp_redirect_multi: Limit the tests in netns")
> Signed-off-by: Hangbin Liu <[email-masked]>
> ---
>  .../selftests/bpf/test_xdp_redirect_multi.sh  | 60 ++++++++++---------
>  1 file changed, 31 insertions(+), 29 deletions(-)
> 
> diff --git a/tools/testing/selftests/bpf/test_xdp_redirect_multi.sh b/tools/testing/selftests/bpf/test_xdp_redirect_multi.sh
> index 05f872740999..cc57cb87e65f 100755
> --- a/tools/testing/selftests/bpf/test_xdp_redirect_multi.sh
> +++ b/tools/testing/selftests/bpf/test_xdp_redirect_multi.sh
> @@ -32,6 +32,11 @@ DRV_MODE="xdpgeneric xdpdrv xdpegress"
>  PASS=0
>  FAIL=0
>  LOG_DIR=$(mktemp -d)
> +declare -a NS
> +NS[0]="ns0-$(mktemp -u XXXXXX)"
> +NS[1]="ns1-$(mktemp -u XXXXXX)"
> +NS[2]="ns2-$(mktemp -u XXXXXX)"
> +NS[3]="ns3-$(mktemp -u XXXXXX)"
>  
>  test_pass()
>  {
> @@ -47,11 +52,9 @@ test_fail()
>  
>  clean_up()
>  {
> -	for i in $(seq $NUM); do
> -		ip link del veth$i 2> /dev/null
> -		ip netns del ns$i 2> /dev/null
> +	for i in $(seq 0 $NUM); do
> +		ip netns del ${NS[$i]} 2> /dev/null

You dropped the `ip link del veth$i` why is this ok?

>  	done
> -	ip netns del ns0 2> /dev/null
>  }