On Mon, Apr 11, 2022 at 03:38:29PM +0200, Joachim Wiberg wrote:
> For some use-cases we may want to change the tcpdump flags used in
> tcpdump_start(). For instance, observing interfaces without the PROMISC
> flag, e.g. to see what's really being forwarded to the bridge interface.
>
> Signed-off-by: Joachim Wiberg <troglobit@xxxxxxxxx>
> ---
> tools/testing/selftests/net/forwarding/lib.sh | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
> mode change 100644 => 100755 tools/testing/selftests/net/forwarding/lib.sh
>
> diff --git a/tools/testing/selftests/net/forwarding/lib.sh b/tools/testing/selftests/net/forwarding/lib.sh
> old mode 100644
> new mode 100755
> index 664b9ecaf228..00cdcab7accf
> --- a/tools/testing/selftests/net/forwarding/lib.sh
> +++ b/tools/testing/selftests/net/forwarding/lib.sh
> @@ -1369,7 +1369,13 @@ tcpdump_start()
> capuser="-Z $SUDO_USER"
> fi
>
> - $ns_cmd tcpdump -e -n -Q in -i $if_name \
> + if [ -z $TCPDUMP_EXTRA_FLAGS ]; then
> + extra_flags=""
> + else
> + extra_flags="$TCPDUMP_EXTRA_FLAGS"
> + fi
> +
> + $ns_cmd tcpdump $extra_flags -e -n -Q in -i $if_name \
Could you call directly "$ns_cmd tcpdump $TCPDUMP_EXTRA_FLAGS ..." here,
without an intermediary "extra_flags" global variable which holds the
same content?
You could initialize it just like the way other variables are
initialized, at the beginning of lib.sh:
TCPDUMP_EXTRA_FLAGS=${TCPDUMP_EXTRA_FLAGS:=}
> -s 65535 -B 32768 $capuser -w $capfile > "$capout" 2>&1 &
> cappid=$!
>
> --
> 2.25.1
>
