Use Pyroute2 "list_tc_qdiscs" function in l3_tc_lib

Change-Id: Ifdccd02411e3c3bae441fc28ab8ed09ff746993c
Related-Bug: #1492714

etc/neutron/rootwrap.d/l3.filters

@@ -31,7 +31,6 @@ find: RegExpFilter, find, root, find, /sys/class/net, -maxdepth, 1, -type, l, -p
 ip_exec: IpNetnsExecFilter, ip, root
 
 # l3_tc_lib
-l3_tc_show_qdisc: RegExpFilter, tc, root, tc, qdisc, show, dev, .+
 l3_tc_add_qdisc_ingress: RegExpFilter, tc, root, tc, qdisc, add, dev, .+, ingress
 l3_tc_add_qdisc_egress: RegExpFilter, tc, root, tc, qdisc, add, dev, .+, root, handle, 1:, htb
 l3_tc_show_filters: RegExpFilter, tc, root, tc, -p, -s, -d, filter, show, dev, .+, parent, .+, prio, 1

neutron/agent/linux/l3_tc_lib.py

@@ -21,8 +21,6 @@ from neutron.agent.linux import tc_lib
 
 LOG = logging.getLogger(__name__)
 
-QDISC_IN_REGEX = re.compile(r"qdisc ingress (\w+:) *")
-QDISC_OUT_REGEX = re.compile(r"qdisc htb (\w+:) *")
 # NOTE(slaweq): in iproute 4.15 chain value was added to filter output and this
 # needs to be included in REGEX
 FILTER_ID_REGEX = re.compile(
@@ -37,20 +35,13 @@ class FloatingIPTcCommandBase(ip_lib.IPDevice):
         ip_wrapper = ip_lib.IPWrapper(self.namespace)
         return ip_wrapper.netns.execute(cmd, run_as_root=True, **kwargs)
 
-    def _get_qdiscs(self):
-        cmd = ['qdisc', 'show', 'dev', self.name]
-        return self._execute_tc_cmd(cmd)
-
     def _get_qdisc_id_for_filter(self, direction):
-        qdisc_results = self._get_qdiscs().split('\n')
+        qdiscs = tc_lib.list_tc_qdiscs(self.name, namespace=self.namespace)
-        for qdisc in qdisc_results:
+        qdisc_type = (tc_lib.TC_QDISC_TYPE_HTB
-            pattern = (QDISC_OUT_REGEX
+                      if direction == constants.EGRESS_DIRECTION
-                       if direction == constants.EGRESS_DIRECTION
+                      else tc_lib.TC_QDISC_TYPE_INGRESS)
-                       else QDISC_IN_REGEX)
+        for qdisc in (qd for qd in qdiscs if qd['qdisc_type'] == qdisc_type):
-            m = pattern.match(qdisc)
+            return qdisc['handle']
-            if m:
-                # No chance to get multiple qdiscs
-                return m.group(1)
 
     def _add_qdisc(self, direction):
         if direction == constants.EGRESS_DIRECTION:

neutron/agent/linux/tc_lib.py

@@ -52,7 +52,10 @@ filters_pattern = re.compile(r"police \w+ rate (\w+) burst (\w+)")
 tbf_pattern = re.compile(
     r"qdisc (\w+) \w+: \w+ refcnt \d rate (\w+) burst (\w+) \w*")
 
-TC_QDISC_TYPES = ['htb', 'tbf', 'ingress']
+TC_QDISC_TYPE_HTB = 'htb'
+TC_QDISC_TYPE_TBF = 'tbf'
+TC_QDISC_TYPE_INGRESS = 'ingress'
+TC_QDISC_TYPES = [TC_QDISC_TYPE_HTB, TC_QDISC_TYPE_TBF, TC_QDISC_TYPE_INGRESS]
 
 TC_QDISC_PARENT = {'root': rtnl.TC_H_ROOT,
                    'ingress': rtnl.TC_H_INGRESS}

neutron/tests/unit/agent/linux/test_l3_tc_lib.py

@@ -15,6 +15,7 @@ from neutron_lib import constants
 from neutron_lib import exceptions
 
 from neutron.agent.linux import l3_tc_lib as tc_lib
+from neutron.agent.linux import tc_lib as base_tc_lib
 from neutron.tests import base
 
 FLOATING_IP_DEVICE_NAME = "qg-device_rfp"
@@ -128,12 +129,8 @@ INGRESS_QSIC_ID = "ffff:"
 EGRESS_QDISC_ID = "1:"
 QDISC_IDS = {constants.INGRESS_DIRECTION: INGRESS_QSIC_ID,
              constants.EGRESS_DIRECTION: EGRESS_QDISC_ID}
-TC_QDISCS = (
+TC_QDISCS = [{'handle': '1:', 'qdisc_type': 'htb', 'parent': 'root'},
-    'qdisc htb %(egress)s root refcnt 2 r2q 10 default 0 '
+             {'handle': 'ffff:', 'qdisc_type': 'ingress', 'parent': 'ingress'}]
-    'direct_packets_stat 6\n'
-    'qdisc ingress %(ingress)s parent ffff:fff1 ----------------\n') % {
-        "egress": EGRESS_QDISC_ID,
-        "ingress": INGRESS_QSIC_ID}
 
 
 class TestFloatingIPTcCommandBase(base.BaseTestCase):
@@ -144,21 +141,9 @@ class TestFloatingIPTcCommandBase(base.BaseTestCase):
             namespace=FLOATING_IP_ROUTER_NAMESPACE)
         self.execute = mock.patch('neutron.agent.common.utils.execute').start()
 
-    def test__get_qdiscs(self):
-        self.tc._get_qdiscs()
-        self.execute.assert_called_once_with(
-            ['ip', 'netns', 'exec', FLOATING_IP_ROUTER_NAMESPACE,
-             'tc', 'qdisc', 'show', 'dev', FLOATING_IP_DEVICE_NAME],
-            run_as_root=True,
-            check_exit_code=True,
-            log_fail_as_error=True,
-            extra_ok_codes=None
-        )
-
     def test__get_qdisc_id_for_filter(self):
-        with mock.patch.object(tc_lib.FloatingIPTcCommandBase,
+        with mock.patch.object(base_tc_lib, 'list_tc_qdiscs',
-                               '_get_qdiscs') as get_qdiscs:
+                               return_value=TC_QDISCS):
-            get_qdiscs.return_value = TC_QDISCS
             q1 = self.tc._get_qdisc_id_for_filter(constants.INGRESS_DIRECTION)
             self.assertEqual(INGRESS_QSIC_ID, q1)
             q2 = self.tc._get_qdisc_id_for_filter(constants.EGRESS_DIRECTION)