Re: [PATCH net 2/2] selftests: mptcp: explicitly trigger the listener diag code-path

Simon Horman
2024-02-26T17:42:05Z

On Thu, Feb 22, 2024 at 03:49:44PM +0100, Matthieu Baerts wrote:
> Hi Simon,
>
> Thank you for the review!
>
> On 22/02/2024 2:13 pm, Simon Horman wrote:
> > On Wed, Feb 22, 2024 at 12:46:59PM +0100, Paolo Abeni wrote:
> >> l The mptcp diag interface already experienced a few locking bugs
> >> that lockdep and appropriate coverage have detected in advance.
> >>
> >> Let's add a test-case triggering the relevant code path, to prevent
> >> similar issues in the future.
> >>
> >> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> >> ---
> >> tools/testing/selftests/net/mptcp/diag.sh | 30 +++++++++++++++++++++++
> >> 1 file changed, 30 insertions(+)
> >>
> >> diff --git a/tools/testing/selftests/net/mptcp/diag.sh b/tools/testing/selftests/net/mptcp/diag.sh
> >> index 60a7009ce1b5..3ab584b38566 100755
> >> --- a/tools/testing/selftests/net/mptcp/diag.sh
> >> +++ b/tools/testing/selftests/net/mptcp/diag.sh
> >> @@ -81,6 +81,21 @@ chk_msk_nr()
> >> __chk_msk_nr "grep -c token:" "$@"
> >> }
> >>
> >> +chk_listener_nr()
> >> +{
> >> + local expected=$1
> >> + local msg="$2"
> >> +
> >> + if [ $expected -gt 0 ] && \
> >> + ! mptcp_lib_kallsyms_has "mptcp_diag_dump_listeners"; then
> >> + printf "%-50s%s\n" "$msg - mptcp" "[ skip ]"
> >> + mptcp_lib_result_skip "many listener sockets"
> >> + else
> >> + __chk_nr "ss -inmlHMON $ns | wc -l" "$expected" "$msg - mptcp"
> >> + fi
> >> + __chk_nr "ss -inmlHtON $ns | wc -l" "$expected" "$msg - subflows"
> >> +}
> >> +
> >> wait_msk_nr()
> >> {
> >> local condition="grep -c token:"
> >> @@ -279,5 +294,20 @@ flush_pids
> >> chk_msk_inuse 0 "many->0"
> >> chk_msk_cestab 0 "many->0"
> >>
> >> +chk_listener_nr 0 "no listener sockets"
> >> +NR_SERVERS=100
> >> +for I in $(seq 1 $NR_SERVERS); do
> >> + ip netns exec $ns ./mptcp_connect -p $((I + 20001)) -l 0.0.0.0 2>&1 >/dev/null &
> >> + mptcp_lib_wait_local_port_listen $ns $((I + 20001))
> >> +done
> >> +
> >> +chk_listener_nr $NR_SERVERS "many listener sockets"
> >> +
> >> +# gracefull termination
> >
> > nit, as you plan to re-spin anyway: graceful
>
> Paolo sent a new version on MPTCP ML only. When applying the new
> version, I fixed this:
>
> https://lore.kernel.org/mptcp/e98b8b07-558c-498a-97fb-dd5cab11e439@kernel.org/
>
> >> +for I in $(seq 1 $NR_SERVERS); do
> >> + echo a | ip netns exec $ns ./mptcp_connect -p $((I + 20001)) 127.0.0.1 2>&1 >/dev/null
> >
> > I'm not sure of the validity of this but shellcheck complains that:
> >
> > SC2069 (warning): To redirect stdout+stderr, 2>&1 must be last (or use '{ cmd > file; } 2>&1' to clarify).
> >
> > Also for the same constriction slightly earlier in this patch.
>
> Good catch!
>
> I should add shellcheck support in our CI to catch that :)
>
> I just applied the suggested modification in our tree [1]. The new
> version that will be sent to netdev will no longer have this issue.
>
> https://github.com/multipath-tcp/mptcp_net-next/commit/31f1460d552c

Thanks Matt,

much appreciated.