Subject: Re: [patch net-next 3/6] selftests: forwarding: add ability to assemble NETIFS array by driver name

From: Benjamin Poirier <[email-masked]>
Date: Fri, 12 Apr 2024 16:38:30 -0400

On 2024-04-12 17:13 +0200, Jiri Pirko wrote:
> From: Jiri Pirko <[email-masked]>
> 
> Allow driver tests to work without specifying the netdevice names.
> Introduce a possibility to search for available netdevices according to
> set driver name. Allow test to specify the name by setting
> NETIF_FIND_DRIVER variable.
> 
> Note that user overrides this either by passing netdevice names on the
> command line or by declaring NETIFS array in custom forwarding.config
> configuration file.
> 
> Signed-off-by: Jiri Pirko <[email-masked]>
> ---
>  tools/testing/selftests/net/forwarding/lib.sh | 39 +++++++++++++++++++
>  1 file changed, 39 insertions(+)
> 
> diff --git a/tools/testing/selftests/net/forwarding/lib.sh b/tools/testing/selftests/net/forwarding/lib.sh
> index 6f6a0f13465f..06633518b3aa 100644
> --- a/tools/testing/selftests/net/forwarding/lib.sh
> +++ b/tools/testing/selftests/net/forwarding/lib.sh
> @@ -55,6 +55,9 @@ declare -A NETIFS=(
>  : "${NETIF_CREATE:=yes}"
>  : "${NETIF_TYPE:=veth}"
>  
> +# Whether to find netdevice according to the specified driver.
> +: "${NETIF_FIND_DRIVER:=}"
> +

This section of the file sets default values for variables that can be
set by users in forwarding.config. NETIF_FIND_DRIVER is more like
NUM_NETIFS, it is set by tests, so I don't think it should be listed
there.

>  # Constants for ping tests:
>  # How many packets should be sent.
>  : "${PING_COUNT:=10}"
> @@ -94,6 +97,42 @@ if [[ ! -v NUM_NETIFS ]]; then
>  	exit $ksft_skip
>  fi
>  
> +##############################################################################
> +# Find netifs by test-specified driver name
> +
> +driver_name_get()
> +{
> +	local dev=$1; shift
> +	local driver_path="/sys/class/net/$dev/device/driver"
> +
> +	if [ ! -L $driver_path ]; then
> +		echo ""
> +	else
> +		basename `realpath $driver_path`
> +	fi
> +}
> +
> +find_netif()
> +{
> +	local ifnames=`ip -j -p link show | jq -e -r ".[].ifname"`

-p and -e can be omitted