selftests: mptcp: userspace pm get addr tests

This patch adds a new helper userspace_pm_get_addr() in mptcp_join.sh.
In it, parse the token value from the output of 'pm_nl_ctl events', then
pass it to pm_nl_ctl get_addr command. Use this helper in userspace pm
dump tests.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Message-Id: <1217349b8d341c11964bb2869d141565c4d355c6.1708422758.git.tanggeliang@kylinos.cn>

tools/testing/selftests/net/mptcp/mptcp_join.sh

@@ -3362,6 +3362,18 @@ userspace_pm_dump()
 	ip netns exec $1 ./pm_nl_ctl dump token $tk
 }
 
+# $1: ns ; $2: id
+userspace_pm_get_addr()
+{
+	local evts=$evts_ns1
+	local tk
+
+	[ "$1" == "$ns2" ] && evts=$evts_ns2
+	tk=$(mptcp_lib_evts_get_info token "$evts")
+
+	ip netns exec $1 ./pm_nl_ctl get $2 token $tk
+}
+
 userspace_pm_chk_dump_addr()
 {
 	local ns="${1}"
@@ -3377,6 +3389,21 @@ userspace_pm_chk_dump_addr()
 	fi
 }
 
+userspace_pm_chk_get_addr()
+{
+	local ns="${1}"
+	local id="${2}"
+	local exp="${3}"
+
+	print_check "get id ${id} addr"
+
+	if mptcp_lib_kallsyms_has "mptcp_userspace_pm_get_addr$"; then
+		check_output "userspace_pm_get_addr ${ns} ${id}" "${exp}"
+	else
+		print_skip
+	fi
+}
+
 userspace_tests()
 {
 	# userspace pm type prevents add_addr
@@ -3471,6 +3498,8 @@ userspace_tests()
 		userspace_pm_chk_dump_addr "${ns1}" \
 			$'id 10 flags signal 10.0.2.1\nid 20 flags signal 10.0.3.1' \
 			"signal"
+		userspace_pm_chk_get_addr "${ns1}" "10" "id 10 flags signal 10.0.2.1"
+		userspace_pm_chk_get_addr "${ns1}" "20" "id 20 flags signal 10.0.3.1"
 		userspace_pm_rm_addr $ns1 10
 		userspace_pm_rm_sf $ns1 "::ffff:10.0.2.1" $SUB_ESTABLISHED
 		userspace_pm_chk_dump_addr "${ns1}" \
@@ -3501,6 +3530,7 @@ userspace_tests()
 		userspace_pm_chk_dump_addr "${ns2}" \
 			"id 20 flags subflow 10.0.3.2" \
 			"subflow"
+		userspace_pm_chk_get_addr "${ns2}" "20" "id 20 flags subflow 10.0.3.2"
 		userspace_pm_rm_addr $ns2 20
 		userspace_pm_rm_sf $ns2 10.0.3.2 $SUB_ESTABLISHED
 		userspace_pm_chk_dump_addr "${ns2}" \