Merge "Add a static FDB entry to fabric-facing bridges"

ovn_bgp_agent/drivers/openstack/utils/ovs.py

@@ -241,6 +241,12 @@ def del_flow(flow, bridge, cookie):
         ['--strict', 'del-flows', bridge, f])
 
 
+def add_fdb_entry(bridge: str, port: str, mac: str, vlan: int = 0):
+    ovn_bgp_agent.privileged.ovs_vsctl.ovs_appctl(
+        ['fdb/add', bridge, port, str(vlan), mac]
+    )
+
+
 def get_flow_info(flow):
     # example:
     # cookie=0x3e7, duration=85.005s, table=0, n_packets=0,

ovn_bgp_agent/drivers/openstack/utils/wire.py

@@ -266,6 +266,7 @@ def _ensure_base_wiring_config_ovn(ovs_idl, ovn_idl):
             # External Bridge connecting to the external networks
             _ensure_ovn_network_link_external(ovn_idl, network, ip, mac)
             _ensure_ingress_flows(bridge, mac, network, provider_cidrs)
+            _ensure_fdb_entry(bridge, mac)
 
     return ovn_bridge_mappings, flows_info
 
@@ -482,6 +483,18 @@ def _ensure_ingress_flows(bridge, mac, switch_name, provider_cidrs):
         ovs.ensure_flow(bridge, flow)
 
 
+def _ensure_fdb_entry(bridge, mac):
+    """Ensure static FDB entries for internal ports of a fabric bridge.
+
+    Fabric-facing bridges need to have a static MAC entry to avoid dynamic
+    re-learning in their FDB as this will lead to drop flows being generated
+    by OVS due to flow table misses.
+    """
+    # The bridge name is also the name of its internal port. The MAC address
+    # is the MAC address of the bridge itself.
+    ovs.add_fdb_entry(bridge, bridge, mac, 0)
+
+
 def _ensure_egress_flows(bridge, patch_ports):
     # outcomming traffic flows
     # patch=`ovs-ofctl show br-provider | grep patch | grep provnet |

ovn_bgp_agent/privileged/ovs_vsctl.py

@@ -42,3 +42,7 @@ def ovs_ofctl(args, timeout=None):
         return ovs_cmd('ovs-ofctl', args, timeout)
     except processutils.ProcessExecutionError:
         return ovs_cmd('ovs-ofctl', args + ['-O', 'OpenFlow13'], timeout)
+
+
+def ovs_appctl(args):
+    return ovs_cmd('ovs-appctl', args)

ovn_bgp_agent/tests/unit/privileged/test_ovs_vsctl.py

@@ -103,3 +103,10 @@ class TestPrivilegedOvsVsctl(test_base.TestCase):
                  mock.call('ovs-ofctl', 'add-flow', 'br-ex', 'dummy-flow',
                            '-O', 'OpenFlow13')]
         self.mock_exc.assert_has_calls(calls)
+
+    def test_ovs_appctl(self):
+        ovs_vsctl.ovs_appctl(
+            ['fdb/add', 'br-fabric', 'br-fabric', '0', 'de:ad:be:ef:ca:fe'])
+        self.mock_exc.assert_called_once_with(
+            'ovs-appctl', 'fdb/add', 'br-fabric', 'br-fabric',
+            '0', 'de:ad:be:ef:ca:fe')