conn_testers: Bump timeout for ICMPv6 echo tests

In IPv6 scenarios NDP can increase round-trip time of ICMPv6 packets over
1 seconds. The patch increases timeout for ICMPv6 to 2 seconds. Note
that this will extend scenarios when ping is supposed to fail.

Change-Id: Iec7d3138aee3fc904312dbc45ef76854ad0ea789
Closes-Bug: 1557946
(cherry picked from commit 420d5c7987)

neutron/tests/common/conn_testers.py

@@ -15,13 +15,24 @@
 import functools
 
 import fixtures
+from neutron_lib import constants as n_consts
 from oslo_utils import uuidutils
 
 from neutron.agent import firewall
+from neutron.agent.linux import ip_lib
 from neutron.common import constants
 from neutron.tests.common import machine_fixtures
 from neutron.tests.common import net_helpers
 
+# NOTE: IPv6 uses NDP for obtaining destination endpoints link address that
+# extends round-trip packet time in ICMP tests. The timeout value should be
+# sufficient for correct scenarios but not too high because of negative
+# tests.
+ICMP_VERSION_TIMEOUTS = {
+    n_consts.IP_VERSION_4: 1,
+    n_consts.IP_VERSION_6: 2,
+}
+
 
 class ConnectionTesterException(Exception):
     pass
@@ -139,8 +150,11 @@ class ConnectionTester(fixtures.Fixture):
 
     def _test_icmp_connectivity(self, direction, protocol, src_port, dst_port):
         src_namespace, ip_address = self._get_namespace_and_address(direction)
+        ip_version = ip_lib.get_ip_version(ip_address)
+        icmp_timeout = ICMP_VERSION_TIMEOUTS[ip_version]
         try:
-            net_helpers.assert_ping(src_namespace, ip_address)
+            net_helpers.assert_ping(src_namespace, ip_address,
+                                    timeout=icmp_timeout)
         except RuntimeError:
             raise ConnectionTesterException(
                 "ICMP packets can't get from %s namespace to %s address" % (