[OVS FW] Clean conntrack entries with mark == CT_MARK_INVALID

In case when security group is removed from port, connections
established to/from port which were hitting some of the removed SG
rules will be marked with CT_MARK_INVALID in the conntrack table.
Due to that such existing connections will be stopped.
But then if SG will be added again to the port, those conntrack entries
marked as invalid will not be removed and those hang connections will
not be revived.
To fix that, this patch adds deletion of the conntrack entries marked
with CT_MARK_INVALID and related to the port of which SG are
updated/added.

Closes-Bug: #1915530
Change-Id: I84718b8ac4d8d6e39426e1c4485c2d7fe28185dd
(cherry picked from commit 1e220d7136)

neutron/agent/linux/ip_conntrack.py

@@ -116,6 +116,7 @@ class IpConntrackManager(object):
         ethertype = rule.get('ethertype')
         protocol = rule.get('protocol')
         direction = rule.get('direction')
+        mark = rule.get('mark')
         cmd = ['conntrack', '-D']
         if protocol is not None:
             # 0 is IP in /etc/protocols, but conntrack will throw an error
@@ -123,6 +124,8 @@ class IpConntrackManager(object):
                 protocol = 'ip'
             cmd.extend(['-p', str(protocol)])
         cmd.extend(['-f', str(ethertype).lower()])
+        if mark is not None:
+            cmd.extend(['-m', str(mark)])
         cmd.append('-d' if direction == 'ingress' else '-s')
         cmd_ns = []
         if namespace:
@@ -173,10 +176,12 @@ class IpConntrackManager(object):
         self._process(device_info_list, rule)
 
     def delete_conntrack_state_by_remote_ips(self, device_info_list,
-                                             ethertype, remote_ips):
+                                             ethertype, remote_ips, mark=None):
         for direction in ['ingress', 'egress']:
             rule = {'ethertype': str(ethertype).lower(),
                     'direction': direction}
+            if mark:
+                rule['mark'] = mark
             self._process(device_info_list, rule, remote_ips)
 
     def _populate_initial_zone_map(self):
@@ -254,3 +259,21 @@ class IpConntrackManager(object):
                 return index + ZONE_START
         # conntrack zones exhausted :( :(
         raise exceptions.CTZoneExhaustedError()
+
+
+class OvsIpConntrackManager(IpConntrackManager):
+
+    def __init__(self, execute=None):
+        super(OvsIpConntrackManager, self).__init__(
+            get_rules_for_table_func=None,
+            filtered_ports={}, unfiltered_ports={},
+            execute=execute, namespace=None, zone_per_port=False)
+
+    def _populate_initial_zone_map(self):
+        self._device_zone_map = {}
+
+    def get_device_zone(self, port, create=False):
+        of_port = port.get('of_port')
+        if of_port is None:
+            return
+        return of_port.vlan_tag

neutron/agent/linux/openvswitch_firewall/firewall.py

@@ -32,6 +32,7 @@ from oslo_utils import netutils
 from neutron._i18n import _
 from neutron.agent.common import ovs_lib
 from neutron.agent import firewall
+from neutron.agent.linux import ip_conntrack
 from neutron.agent.linux.openvswitch_firewall import constants as ovsfw_consts
 from neutron.agent.linux.openvswitch_firewall import exceptions
 from neutron.agent.linux.openvswitch_firewall import iptables
@@ -481,6 +482,7 @@ class OVSFirewallDriver(firewall.FirewallDriver):
         self._deferred = False
         self.iptables_helper = iptables.Helper(self.int_br.br)
         self.iptables_helper.load_driver_if_needed()
+        self.ipconntrack = ip_conntrack.OvsIpConntrackManager()
         self._initialize_firewall()
 
         callbacks_registry.subscribe(
@@ -611,6 +613,12 @@ class OVSFirewallDriver(firewall.FirewallDriver):
         return get_physical_network_from_other_config(
             self.int_br.br, port_name)
 
+    def _delete_invalid_conntrack_entries_for_port(self, port, of_port):
+        port['of_port'] = of_port
+        for ethertype in [lib_const.IPv4, lib_const.IPv6]:
+            self.ipconntrack.delete_conntrack_state_by_remote_ips(
+                [port], ethertype, set(), mark=ovsfw_consts.CT_MARK_INVALID)
+
     def get_ofport(self, port):
         port_id = port['device']
         return self.sg_port_map.ports.get(port_id)
@@ -665,6 +673,7 @@ class OVSFirewallDriver(firewall.FirewallDriver):
                 self._update_flows_for_port(of_port, old_of_port)
             else:
                 self._set_port_filters(of_port)
+            self._delete_invalid_conntrack_entries_for_port(port, of_port)
         except exceptions.OVSFWPortNotFound as not_found_error:
             LOG.info("port %(port_id)s does not exist in ovsdb: %(err)s.",
                      {'port_id': port['device'],
@@ -704,6 +713,8 @@ class OVSFirewallDriver(firewall.FirewallDriver):
             else:
                 self._set_port_filters(of_port)
 
+            self._delete_invalid_conntrack_entries_for_port(port, of_port)
+
         except exceptions.OVSFWPortNotFound as not_found_error:
             LOG.info("port %(port_id)s does not exist in ovsdb: %(err)s.",
                      {'port_id': port['device'],

neutron/tests/unit/agent/linux/openvswitch_firewall/test_firewall.py

@@ -438,6 +438,9 @@ class TestOVSFirewallDriver(base.BaseTestCase):
             ovs_lib, 'OVSBridge', autospec=True).start()
         securitygroups_rpc.register_securitygroups_opts()
         self.firewall = ovsfw.OVSFirewallDriver(mock_bridge)
+        self.delete_invalid_conntrack_entries_mock = mock.patch.object(
+            self.firewall.ipconntrack,
+            "delete_conntrack_state_by_remote_ips").start()
         self.mock_bridge = self.firewall.int_br
         self.mock_bridge.reset_mock()
         self.fake_ovs_port = FakeOVSPort('port', 1, '00:00:00:00:00:00')
@@ -462,6 +465,16 @@ class TestOVSFirewallDriver(base.BaseTestCase):
              'direction': constants.EGRESS_DIRECTION}]
         self.firewall.update_security_group_rules(2, security_group_rules)
 
+    def _assert_invalid_conntrack_entries_deleted(self, port_dict):
+        port_dict['of_port'] = mock.Mock(vlan_tag=10)
+        self.delete_invalid_conntrack_entries_mock.assert_has_calls([
+            mock.call(
+                [port_dict], constants.IPv4, set(),
+                mark=ovsfw_consts.CT_MARK_INVALID),
+            mock.call(
+                [port_dict], constants.IPv6, set(),
+                mark=ovsfw_consts.CT_MARK_INVALID)])
+
     @property
     def port_ofport(self):
         return self.mock_bridge.br.get_vif_port_by_id.return_value.ofport
@@ -619,6 +632,7 @@ class TestOVSFirewallDriver(base.BaseTestCase):
         calls = self.mock_bridge.br.add_flow.call_args_list
         for call in exp_ingress_classifier, exp_egress_classifier, filter_rule:
             self.assertIn(call, calls)
+        self._assert_invalid_conntrack_entries_deleted(port_dict)
 
     def test_prepare_port_filter_port_security_disabled(self):
         port_dict = {'device': 'port-id',
@@ -629,6 +643,7 @@ class TestOVSFirewallDriver(base.BaseTestCase):
                 self.firewall, 'initialize_port_flows') as m_init_flows:
             self.firewall.prepare_port_filter(port_dict)
         self.assertFalse(m_init_flows.called)
+        self.delete_invalid_conntrack_entries_mock.assert_not_called()
 
     def _test_initialize_port_flows_dvr_conntrack_direct(self, network_type):
         port_dict = {
@@ -800,6 +815,7 @@ class TestOVSFirewallDriver(base.BaseTestCase):
         self.assertFalse(self.mock_bridge.br.delete_flows.called)
         self.firewall.prepare_port_filter(port_dict)
         self.assertTrue(self.mock_bridge.br.delete_flows.called)
+        self._assert_invalid_conntrack_entries_deleted(port_dict)
 
     def test_update_port_filter(self):
         port_dict = {'device': 'port-id',
@@ -831,6 +847,7 @@ class TestOVSFirewallDriver(base.BaseTestCase):
             table=ovs_consts.RULES_EGRESS_TABLE)]
         self.mock_bridge.br.add_flow.assert_has_calls(
             filter_rules, any_order=True)
+        self._assert_invalid_conntrack_entries_deleted(port_dict)
 
     def test_update_port_filter_create_new_port_if_not_present(self):
         port_dict = {'device': 'port-id',
@@ -850,15 +867,18 @@ class TestOVSFirewallDriver(base.BaseTestCase):
         self.assertFalse(self.mock_bridge.br.delete_flows.called)
         self.assertTrue(initialize_port_flows_mock.called)
         self.assertTrue(add_flows_from_rules_mock.called)
+        self._assert_invalid_conntrack_entries_deleted(port_dict)
 
     def test_update_port_filter_port_security_disabled(self):
         port_dict = {'device': 'port-id',
                      'security_groups': [1]}
         self._prepare_security_group()
         self.firewall.prepare_port_filter(port_dict)
+        self.delete_invalid_conntrack_entries_mock.reset_mock()
         port_dict['port_security_enabled'] = False
         self.firewall.update_port_filter(port_dict)
         self.assertTrue(self.mock_bridge.br.delete_flows.called)
+        self.delete_invalid_conntrack_entries_mock.assert_not_called()
 
     def test_update_port_filter_applies_added_flows(self):
         """Check flows are applied right after _set_flows is called."""
@@ -879,6 +899,7 @@ class TestOVSFirewallDriver(base.BaseTestCase):
         self.mock_bridge.br.get_vif_port_by_id.return_value = None
         self.firewall.update_port_filter(port_dict)
         self.assertTrue(self.mock_bridge.br.delete_flows.called)
+        self._assert_invalid_conntrack_entries_deleted(port_dict)
 
     def test_remove_port_filter(self):
         port_dict = {'device': 'port-id',

neutron/tests/unit/agent/linux/test_ip_conntrack.py

@@ -39,3 +39,26 @@ class IPConntrackTestCase(base.BaseTestCase):
         dev_info_list = [dev_info for _ in range(10)]
         self.mgr._delete_conntrack_state(dev_info_list, rule)
         self.assertEqual(1, len(self.execute.mock_calls))
+
+
+class OvsIPConntrackTestCase(IPConntrackTestCase):
+
+    def setUp(self):
+        super(IPConntrackTestCase, self).setUp()
+        self.execute = mock.Mock()
+        self.mgr = ip_conntrack.OvsIpConntrackManager(self.execute)
+
+    def test_delete_conntrack_state_dedupes(self):
+        rule = {'ethertype': 'IPv4', 'direction': 'ingress'}
+        dev_info = {
+            'device': 'tapdevice',
+            'fixed_ips': ['1.2.3.4'],
+            'of_port': mock.Mock(of_port=10)}
+        dev_info_list = [dev_info for _ in range(10)]
+        self.mgr._delete_conntrack_state(dev_info_list, rule)
+        self.assertEqual(1, len(self.execute.mock_calls))
+
+    def test_get_device_zone(self):
+        of_port = mock.Mock(vlan_tag=10)
+        port = {'id': 'port-id', 'of_port': of_port}
+        self.assertEqual(10, self.mgr.get_device_zone(port))