Re: [PATCH mptcp-next v14 4/7] selftests: mptcp: userspace pm remove initial subflow

[Geliang Tang <geliang.tang@suse.com>]

On Wed, Oct 11, 2023 at 05:57:42PM +0200, Matthieu Baerts wrote:
> Hi Geliang,
> 
> On 11/10/2023 15:34, Geliang Tang wrote:
> > This patch adds a selftest for userpsace PM to remove the initial
> > subflow. Use userspace_pm_add_sf() to add a subflow, and pass initial
> > ip address to userspace_pm_rm_sf() to remove the initial subflow.
> > 
> > Signed-off-by: Geliang Tang <geliang.tang@suse.com>
> > ---
> >  .../testing/selftests/net/mptcp/mptcp_join.sh | 22 +++++++++++++++++++
> >  1 file changed, 22 insertions(+)
> > 
> > diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
> > index ab6908b7b143..e1304383057c 100755
> > --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
> > +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
> > @@ -3507,6 +3507,28 @@ userspace_tests()
> >  		kill_events_pids
> >  		wait $tests_pid
> >  	fi
> > +
> > +	# userspace pm remove initial subflow
> > +	if reset_with_events "userspace pm remove initial subflow" &&
> > +	   continue_if mptcp_lib_has_file '/proc/sys/net/mptcp/pm_type'; then
> > +		set_userspace_pm $ns2
> > +		pm_nl_set_limits $ns1 0 1
> > +		speed=10 \
> > +			run_tests $ns1 $ns2 10.0.1.1 &
> > +		local tests_pid=$!
> > +		wait_mpj $ns2
> > +		userspace_pm_add_sf $ns2 10.0.3.2 20
> > +		chk_join_nr 1 1 1
> > +		chk_mptcp_info subflows 1 subflows 1
> > +		chk_subflows_total 2 2
> > +		userspace_pm_rm_sf $ns2 10.0.1.2
> 
> If this command removes the initial subflow ...
> 
> > +		chk_rm_nr 0 1
> 
> (it is a bit confusing, we could think there are RM_ADDR being sent
> here. If you need to change something else, can you add a comment here
> that we don't look at the counter linked to the RM_ADDR but to the one
> linked to the subflows that have been removed please?)
> 
> > +		chk_rst_nr 0 0 invert
> > +		chk_mptcp_info subflows 1 subflows 1
> 
> ... that's normal to still have 1 "extra subflow" here but ...
> 
> > +		chk_subflows_total 2 2
> 
> ... this should be "1 1", no? One subflow has been removed in between,
> so we should not have the same counter as before, no?

It will be "2 1" if we test TCPF_FIN_WAIT2 as well as TCPF_CLOSE in
__mptcp_has_initial_subflow too. This is no subflow removed in ns1, one
subflow has been removed in ns2. Patch 7 will get "2 1" too.

> 
> Cheers,
> Matt
> -- 
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