Re: [PATCH net-next v2 2/2] selftests: net: add test for dst hint mechanism with directed broadcast addresses

[Oscar Maes <oscmaes92@gmail.com>]

On Tue, Aug 19, 2025 at 12:56:58PM +0200, Paolo Abeni wrote:
> On 8/14/25 4:03 PM, Oscar Maes wrote:
> >  tools/testing/selftests/net/route_hint.sh | 58 +++++++++++++++++++++++
> >  1 file changed, 58 insertions(+)
> >  create mode 100755 tools/testing/selftests/net/route_hint.sh
> 
> You must additionally update the net selftest Makefile to include the
> new test.
> 

My bad.

> > 
> > diff --git a/tools/testing/selftests/net/route_hint.sh b/tools/testing/selftests/net/route_hint.sh
> > new file mode 100755
> > index 000000000000..fab08d8b742d
> > --- /dev/null
> > +++ b/tools/testing/selftests/net/route_hint.sh
> > @@ -0,0 +1,58 @@
> > +#!/bin/bash
> > +# SPDX-License-Identifier: GPL-2.0
> > +
> > +# This test ensures directed broadcast routes use dst hint mechanism
> > +
> > +CLIENT_NS=$(mktemp -u client-XXXXXXXX)
> > +CLIENT_IP4="192.168.0.1"
> > +
> > +SERVER_NS=$(mktemp -u server-XXXXXXXX)
> > +SERVER_IP4="192.168.0.2"
> 
> > +
> > +BROADCAST_ADDRESS="192.168.0.255"
> > +
> > +setup() {
> > +	ip netns add "${CLIENT_NS}"
> > +	ip netns add "${SERVER_NS}"
> 
> You can/should use setup_ns() from lib.sh to avoid some duplicate code
> 
> > +
> > +	ip -net "${SERVER_NS}" link add link1 type veth peer name link0 netns "${CLIENT_NS}"
> > +
> > +	ip -net "${CLIENT_NS}" link set link0 up
> > +	ip -net "${CLIENT_NS}" addr add "${CLIENT_IP4}/24" dev link0
> > +
> > +	ip -net "${SERVER_NS}" link set link1 up
> > +	ip -net "${SERVER_NS}" addr add "${SERVER_IP4}/24" dev link1
> > +
> > +	ip netns exec "${CLIENT_NS}" ethtool -K link0 tcp-segmentation-offload off
> > +	ip netns exec "${SERVER_NS}" sh -c "echo 500000000 > /sys/class/net/link1/gro_flush_timeout"
> > +	ip netns exec "${SERVER_NS}" sh -c "echo 1 > /sys/class/net/link1/napi_defer_hard_irqs"
> > +	ip netns exec "${SERVER_NS}" ethtool -K link1 generic-receive-offload on
> > +}
> > +
> > +cleanup() {
> > +	ip -net "${SERVER_NS}" link del link1
> > +	ip netns del "${CLIENT_NS}"
> > +	ip netns del "${SERVER_NS}"
> > +}
> > +
> > +directed_bcast_hint_test()
> > +{
> > +	echo "Testing for directed broadcast route hint"
> > +
> > +	orig_in_brd=$(ip netns exec "${SERVER_NS}" lnstat -k in_brd -s0 -i1 -c1 | tr -d ' |')
> 
> Likely using the '--json' argument and 'jq' will make the parsing more
> clear.
> 
> > +	ip netns exec "${CLIENT_NS}" mausezahn link0 -a own -b bcast -A "${CLIENT_IP4}" \
> > +		-B "${BROADCAST_ADDRESS}" -c1 -t tcp "sp=1-100,dp=1234,s=1,a=0" -p 5 -q
> 
> You should check for mausezahn presence and ev. error out with error
> code 4 (ksft_skip)
> 
> > +	sleep 1
> > +	new_in_brd=$(ip netns exec "${SERVER_NS}" lnstat -k in_brd -s0 -i1 -c1 | tr -d ' |')
> > +
> > +	res=$(echo "${new_in_brd} - ${orig_in_brd}" | bc)
> > +
> > +	[ "${res}" -lt 100 ]
> 
> It would be helpful additionally printing the test result:  '[ ok ]' /
> '[fail] expected ... found ...'
> 
> /P
> 

Will fix everything in v3 and resend shortly.