[PATCH 6.1.y] selftests: mptcp: join: check re-re-adding ID 0 endp

["Matthieu Baerts (NGI0)" <matttbe@kernel.org>]

commit d397d7246c11ca36c33c932bc36d38e3a79e9aa0 upstream.

This test extends "delete and re-add" to validate the previous commit:
when the endpoint linked to the initial subflow (ID 0) is re-added
multiple times, it was no longer being used, because the internal linked
counters are not decremented for this special endpoint: it is not an
additional endpoint.

Here, the "del/add id 0" steps are done 3 times to unsure this case is
validated.

The 'Fixes' tag here below is the same as the one from the previous
commit: this patch here is not fixing anything wrong in the selftests,
but it validates the previous fix for an issue introduced by this commit
ID.

Fixes: 3ad14f54bd74 ("mptcp: more accurate MPC endpoint tracking")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
[ Conflicts in mptcp_join.sh, because the helpers are different in this
  version:
  - run_tests has been modified a few times to reduce the number of
    positional parameters
  - no chk_mptcp_info helper
  - chk_subflow_nr taking an extra parameter
  - kill_tests_wait instead of mptcp_lib_kill_wait ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 .../testing/selftests/net/mptcp/mptcp_join.sh | 21 +++++++++++--------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index bed980b04624..79e9cac89cd2 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -3272,7 +3272,7 @@ endpoint_tests()
 		pm_nl_set_limits $ns2 0 3
 		pm_nl_add_endpoint $ns2 10.0.1.2 id 1 dev ns2eth1 flags subflow
 		pm_nl_add_endpoint $ns2 10.0.2.2 id 2 dev ns2eth2 flags subflow
-		run_tests $ns1 $ns2 10.0.1.1 4 0 0 speed_20 2>/dev/null &
+		run_tests $ns1 $ns2 10.0.1.1 4 0 0 speed_5 2>/dev/null &
 
 		wait_mpj $ns2
 		pm_nl_del_endpoint $ns2 2 10.0.2.2
@@ -3293,18 +3293,21 @@ endpoint_tests()
 		wait_mpj $ns2
 		chk_subflow_nr "" "after no reject" 3
 
-		pm_nl_del_endpoint $ns2 1 10.0.1.2
-		sleep 0.5
-		chk_subflow_nr "" "after delete id 0" 2
+		local i
+		for i in $(seq 3); do
+			pm_nl_del_endpoint $ns2 1 10.0.1.2
+			sleep 0.5
+			chk_subflow_nr "" "after delete id 0 ($i)" 2
 
-		pm_nl_add_endpoint $ns2 10.0.1.2 id 1 dev ns2eth1 flags subflow
-		wait_mpj $ns2
-		chk_subflow_nr "" "after re-add id 0" 3
+			pm_nl_add_endpoint $ns2 10.0.1.2 id 1 dev ns2eth1 flags subflow
+			wait_mpj $ns2
+			chk_subflow_nr "" "after re-add id 0 ($i)" 3
+		done
 
 		kill_tests_wait
 
-		chk_join_nr 4 4 4
-		chk_rm_nr 2 2
+		chk_join_nr 6 6 6
+		chk_rm_nr 4 4
 	fi
 
 	# remove and re-add
-- 
2.45.2