This patch adds a new helper userspace_pm_dump() to dump addresses
for the userspace PM. Use this helper to check whether an ID 0 subflow
is listed in the output of dump command after creating an ID 0 subflow
in "userspace pm create id 0 subflow" test.

Signed-off-by: Geliang Tang <geliang.tang@linux.dev>
---
 tools/testing/selftests/net/mptcp/mptcp_join.sh | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index f4043baa59c6..a92fb5469621 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -3361,6 +3361,18 @@ userspace_pm_rm_sf()
 	wait_rm_sf $1 "${cnt}"
 }
 
+# $1: ns
+userspace_pm_dump()
+{
+	local evts=$evts_ns1
+	local tk
+
+	[ "$1" == "$ns2" ] && evts=$evts_ns2
+	tk=$(mptcp_lib_evts_get_info token "$evts")
+
+	ip netns exec $1 ./pm_nl_ctl dump token $tk
+}
+
 check_output()
 {
 	local cmd="$1"
@@ -3522,6 +3534,9 @@ userspace_tests()
 		chk_mptcp_info subflows 0 subflows 0
 		chk_subflows_total 1 1
 		userspace_pm_add_sf $ns2 10.0.3.2 0
+		check_output "userspace_pm_dump $ns2" \
+			     "id 0 flags subflow 10.0.3.2" \
+			     "      dump addrs id 0 subflow"
 		chk_join_nr 1 1 1
 		chk_mptcp_info subflows 1 subflows 1
 		chk_subflows_total 2 2
-- 
2.39.2