Add unittest

Signed-off-by: Longxiang Lyu <[email protected]>

Author: lolyu

tests/test_vlan.py

@@ -436,6 +436,48 @@ def test_VlanHostIf(self, dvs):
         self.dvs_vlan.get_and_verify_vlan_ids(0)
         self.dvs_vlan.get_and_verify_vlan_hostif_ids(len(dvs.asic_db.hostif_name_map) - 1)
 
+    def test_VlanMemberLinkDown(self, dvs):
+
+        # TODO: add_ip_address has a dependency on cdb within dvs,
+        # so we still need to setup the db. This should be refactored.
+        dvs.setup_db()
+
+        vlan = "1000"
+        vlan_ip = "192.168.0.1/21"
+        interface = "Ethernet0"
+        vlan_interface = "Vlan%s" % vlan
+        server_ip = "192.168.0.100"
+        vlan_intf_sysctl_param_path = "/proc/sys/net/ipv4/conf/%s/arp_evict_nocarrier" % vlan_interface
+
+        self.dvs_vlan.create_vlan(vlan)
+        vlan_oid = self.dvs_vlan.get_and_verify_vlan_ids(1)[0]
+        self.dvs_vlan.verify_vlan(vlan_oid, vlan)
+        self.dvs_vlan.create_vlan_member(vlan, interface)
+        self.dvs_vlan.verify_vlan_member(vlan_oid, interface)
+        dvs.set_interface_status(interface, "up")
+        dvs.add_ip_address(vlan_interface, vlan_ip)
+        dvs.runcmd("ip neigh replace %s lladdr 11:22:33:44:55:66 dev %s nud stale" % (server_ip, vlan_interface))
+
+        neigh_oid = self.dvs_vlan.app_db.wait_for_n_keys("NEIGH_TABLE", 1)[0]
+        assert vlan_interface in neigh_oid and server_ip in neigh_oid
+
+        # NOTE: arp_evict_nocarrier is available for kernel >= v5.16 and current
+        # docker-sonic-vs is based on kernel v5.4.0, so test only if this sysctl
+        # param is present
+        rc, res = dvs.runcmd("cat %s" % vlan_intf_sysctl_param_path)
+        if rc == 0:
+            assert res.strip() == "0"
+            dvs.set_interface_status(interface, "down")
+            neigh_oid = self.dvs_vlan.app_db.wait_for_n_keys("NEIGH_TABLE", 1)[0]
+            assert vlan_interface in neigh_oid and server_ip in neigh_oid
+
+        dvs.runcmd("ip neigh flush all")
+        dvs.remove_ip_address(vlan_interface, vlan_ip)
+        self.dvs_vlan.remove_vlan_member(vlan, interface)
+        self.dvs_vlan.get_and_verify_vlan_member_ids(0)
+        self.dvs_vlan.remove_vlan(vlan)
+        self.dvs_vlan.get_and_verify_vlan_ids(0)
+
 # Add Dummy always-pass test at end as workaroud
 # for issue when Flaky fail on final test it invokes module tear-down before retrying
 def test_nonflaky_dummy():