Don't add arp responder for non tunnel network port

When the vlan and vxlan both exist in env, and l2population
and arp_responder are enabled, if we update a port's ip address
from vlan network, there will be arp responder related flows
added into br-tun, this will cause too many arp reply for
one arp request, and vm connections will be unnormal.

Closes-Bug: #1824504
Change-Id: I1b6154b9433a9442d3e0118dedfa01c4a9b4740b
(cherry picked from commit 5301ecf41b)

neutron/plugins/ml2/drivers/l2pop/mech_driver.py

@@ -120,6 +120,13 @@ class L2populationMechanismDriver(api.MechanismDriver):
         if not agent_host:
             return
 
+        # We should not add arp responder for non tunnel network type
+        port_context = context._plugin_context
+        agent = l2pop_db.get_agent_by_host(port_context, agent_host)
+        segment = context.bottom_bound_segment
+        if not self._validate_segment(segment, port['id'], agent):
+            return
+
         agent_ip = l2pop_db.get_agent_ip_by_host(context._plugin_context,
                                                  agent_host)
 

neutron/tests/unit/plugins/ml2/drivers/l2pop/test_mech_driver.py

@@ -1087,6 +1087,35 @@ class TestL2PopulationRpcTestCase(test_plugin.Ml2PluginV2TestCase):
                 self.mock_fanout.assert_called_with(
                     mock.ANY, 'add_fdb_entries', add_expected)
 
+    def test_fixed_ips_changed_vlan(self):
+        self._register_ml2_agents()
+
+        with self.subnet(network=self._network2) as subnet:
+            host_arg = {portbindings.HOST_ID: HOST}
+            fixed_ips = [{'subnet_id': subnet['subnet']['id'],
+                          'ip_address': '10.0.0.2'}]
+            with self.port(subnet=subnet, cidr='10.0.0.0/24',
+                           device_owner=DEVICE_OWNER_COMPUTE,
+                           arg_list=(portbindings.HOST_ID,),
+                           fixed_ips=fixed_ips,
+                           **host_arg) as port:
+                p = port['port']
+
+                device = 'tap' + p['id']
+
+                self.callbacks.update_device_up(self.adminContext,
+                                                agent_id=HOST,
+                                                device=device)
+
+                data = {'port': {'fixed_ips': [{'ip_address': '10.0.0.2'},
+                                               {'ip_address': '10.0.0.10'}]}}
+                self.new_update_request('ports', data, p['id'])
+                l2pop_mech = l2pop_mech_driver.L2populationMechanismDriver()
+                l2pop_mech.L2PopulationAgentNotify = mock.Mock()
+                l2notify = l2pop_mech.L2PopulationAgentNotify
+                l2notify.update_fdb_entries = mock.Mock()
+                self.assertFalse(l2notify.update_fdb_entries.called)
+
     def test_fixed_ips_changed(self):
         self._register_ml2_agents()