Subject: Re: [PATCH net-next v3 4/9] selftests: net: update some helpers to use run_on

From: Petr Machata <[email-masked]>
Date: Fri, 20 Mar 2026 12:22:02 +0100

Ioana Ciornei <[email-masked]> writes:

> Update some helpers so that they are capable to run commands on
> different targets than the local one. This patch makes the necesasy
> modification for those helpers / sections of code which are needed for
> the ethtool_rmon.sh test that will be converted in the next patches.
>
> For example, mac_addr_prepare() and mac_addr_restore() used when
> STABLE_MAC_ADDRS=yes need to ensure stable MAC addresses on interfaces
> located even in other namespaces. In order to do that, append the 'ip
> link' commands with a 'run_on $dev' tag.
>
> The same run_on is necessary also when verifying if all the interfaces
> listed in NETIFS are indeed available.
>
> Signed-off-by: Ioana Ciornei <[email-masked]>

This looks good, but I'm unhappy with some overlong lines again :)

> ---
> Changes in v3:
> - added some more double quotes
> Changes in v2:
> - patch is new
>
>  tools/testing/selftests/net/forwarding/lib.sh | 17 ++++++++++-------
>  tools/testing/selftests/net/lib.sh            |  2 +-
>  2 files changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/tools/testing/selftests/net/forwarding/lib.sh b/tools/testing/selftests/net/forwarding/lib.sh
> index fb5aa56343e1..f76de37d0caf 100644
> --- a/tools/testing/selftests/net/forwarding/lib.sh
> +++ b/tools/testing/selftests/net/forwarding/lib.sh
> @@ -530,10 +530,10 @@ mac_addr_prepare()
>  		dev=${NETIFS[p$i]}
>  		new_addr=$(printf "00:01:02:03:04:%02x" $i)
>  
> -		MAC_ADDR_ORIG["$dev"]=$(ip -j link show dev $dev | jq -e '.[].address')
> +		MAC_ADDR_ORIG["$dev"]=$(run_on "$dev" ip -j link show dev "$dev" | jq -e '.[].address')

Here.

>  		# Strip quotes
>  		MAC_ADDR_ORIG["$dev"]=${MAC_ADDR_ORIG["$dev"]//\"/}
> -		ip link set dev $dev address $new_addr
> +		run_on "$dev" ip link set dev "$dev" address $new_addr
>  	done
>  }
>  
> @@ -543,7 +543,7 @@ mac_addr_restore()
>  
>  	for ((i = 1; i <= NUM_NETIFS; ++i)); do
>  		dev=${NETIFS[p$i]}
> -		ip link set dev $dev address ${MAC_ADDR_ORIG["$dev"]}
> +		run_on "$dev" ip link set dev "$dev" address ${MAC_ADDR_ORIG["$dev"]}

And here.

>  	done
>  }
>  
> @@ -556,7 +556,9 @@ if [[ "$STABLE_MAC_ADDRS" = "yes" ]]; then
>  fi
>  
>  for ((i = 1; i <= NUM_NETIFS; ++i)); do
> -	ip link show dev ${NETIFS[p$i]} &> /dev/null
> +	int="${NETIFS[p$i]}"
> +
> +	run_on "$int" ip link show dev "$int" &> /dev/null
>  	if [[ $? -ne 0 ]]; then
>  		echo "SKIP: could not find all required interfaces"
>  		exit $ksft_skip
> @@ -639,7 +641,7 @@ setup_wait_dev_with_timeout()
>  	local i
>  
>  	for ((i = 1; i <= $max_iterations; ++i)); do
> -		ip link show dev $dev up \
> +		run_on "$dev" ip link show dev "$dev" up \
>  			| grep 'state UP' &> /dev/null
>  		if [[ $? -ne 0 ]]; then
>  			sleep 1
> @@ -944,9 +946,10 @@ ethtool_std_stats_get()
>  	local src=$1; shift
>  
>  	if [[ "$grp" == "pause" ]]; then
> -		ethtool -I --json -a "$dev" | jq --arg name "$name" '.[].statistics[$name]'
> +		run_on "$dev" ethtool -I --json -a "$dev" | \
> +			jq --arg name "$name" '.[].statistics[$name]'

Oh, I see, you fold it here. Um, would be better in 1/9 though :)

>  	else
> -		ethtool --json -S "$dev" --groups "$grp" -- --src "$src" | \
> +		run_on "$dev" ethtool --json -S "$dev" --groups "$grp" -- --src "$src" | \
>  			jq --arg grp "$grp" --arg name "$name" '.[][$grp][$name]'

This needs to be folded as well.

>  	fi
>  }
> diff --git a/tools/testing/selftests/net/lib.sh b/tools/testing/selftests/net/lib.sh
> index f7c54d05758e..14f262a593c9 100644
> --- a/tools/testing/selftests/net/lib.sh
> +++ b/tools/testing/selftests/net/lib.sh
> @@ -518,7 +518,7 @@ mac_get()
>  {
>  	local if_name=$1
>  
> -	ip -j link show dev $if_name | jq -r '.[]["address"]'
> +	run_on "$if_name" ip -j link show dev "$if_name" | jq -r '.[]["address"]'
>  }
>  
>  kill_process()