tests/topotests/bgp_tcp_mss/test_bgp_tcp_mss.py

   1 #!/usr/bin/env python
   2
   3 #
   4 # bgp_tcp_mss.py
   5 # Part of NetDEF Topology Tests
   6 #
   7 # Copyright (c) 2021 by
   8 # Abhinay Ramesh <rabhinay@vmware.com>
   9 #
  10 # Permission to use, copy, modify, and/or distribute this software
  11 # for any purpose with or without fee is hereby granted, provided
  12 # that the above copyright notice and this permission notice appear
  13 # in all copies.
  14 #
  15 # THE SOFTWARE IS PROVIDED "AS IS" AND NETDEF DISCLAIMS ALL WARRANTIES
  16 # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  17 # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NETDEF BE LIABLE FOR
  18 # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY
  19 # DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  20 # WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  21 # ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  22 # OF THIS SOFTWARE.
  23 #
  24
  25 """
  26 bgp_tcp_mss.py:
  27
  28 Test if works the following commands:
  29 router bgp 65000
  30   neighbor 192.168.255.2 tcp-mss 500
  31
  32 Need to verify if the tcp-mss value is reflected in the TCP session.
  33 """
  34
  35 import os
  36 import sys
  37 import json
  38 import time
  39 import pytest
  40 import functools
  41
  42 # add after imports, before defining classes or functions:
  43 pytestmark = [pytest.mark.bgpd]
  44
  45 CWD = os.path.dirname(os.path.realpath(__file__))
  46 sys.path.append(os.path.join(CWD, "../"))
  47
  48 # pylint: disable=C0413
  49 from lib import topotest
  50 from lib.topogen import Topogen, TopoRouter, get_topogen
  51 from lib.topolog import logger
  52 from mininet.topo import Topo
  53
  54 pytestmark = [pytest.mark.bgpd]
  55
  56
  57 class TemplateTopo(Topo):
  58     def build(self, *_args, **_opts):
  59         tgen = get_topogen(self)
  60
  61         for routern in range(1, 3):
  62             tgen.add_router("r{}".format(routern))
  63
  64         switch = tgen.add_switch("s1")
  65         switch.add_link(tgen.gears["r1"])
  66         switch.add_link(tgen.gears["r2"])
  67
  68
  69 def setup_module(mod):
  70     tgen = Topogen(TemplateTopo, mod.__name__)
  71     tgen.start_topology()
  72
  73     router_list = tgen.routers()
  74
  75     for i, (rname, router) in enumerate(router_list.items(), 1):
  76         router.load_config(
  77             TopoRouter.RD_ZEBRA, os.path.join(CWD, "{}/zebra.conf".format(rname))
  78         )
  79         router.load_config(
  80             TopoRouter.RD_BGP, os.path.join(CWD, "{}/bgpd.conf".format(rname))
  81         )
  82
  83     tgen.start_router()
  84
  85
  86 def teardown_module(mod):
  87     tgen = get_topogen()
  88     tgen.stop_topology()
  89
  90
  91 def test_bgp_tcp_mss():
  92     tgen = get_topogen()
  93
  94     if tgen.routers_have_failure():
  95         pytest.skip(tgen.errors)
  96
  97     router1 = tgen.gears["r1"]
  98     router2 = tgen.gears["r2"]
  99
 100     def _bgp_converge(router):
 101         output = json.loads(router.vtysh_cmd("show ip bgp neighbor 192.168.255.2 json"))
 102         expected = {
 103             "192.168.255.2": {
 104                 "bgpState": "Established",
 105                 "addressFamilyInfo": {"ipv4Unicast": {"acceptedPrefixCounter": 0}},
 106             }
 107         }
 108         return topotest.json_cmp(output, expected)
 109
 110     def _bgp_conf_tcp_mss(router, as_num, neigh):
 111         router.vtysh_cmd(
 112             """configure terminal
 113                router bgp {0}
 114                  neighbor {1} tcp-mss 500""".format(
 115                 as_num, neigh
 116             )
 117         )
 118
 119     def _bgp_clear_session(router):
 120         router.vtysh_cmd("clear bgp *")
 121
 122     def _bgp_check_neighbor_tcp_mss(router, neigh):
 123         output = json.loads(router.vtysh_cmd("show bgp neighbor {} json".format(neigh)))
 124         expected = {
 125             "{}".format(neigh): {"bgpTcpMssConfigured": 500, "bgpTcpMssSynced": 488}
 126         }
 127         return topotest.json_cmp(output, expected)
 128
 129     logger.info("Check if neighbor sessions are up in {}".format(router1.name))
 130     test_func = functools.partial(_bgp_converge, router1)
 131     success, result = topotest.run_and_expect(test_func, None, count=15, wait=0.5)
 132     assert result is None, 'Failed to see BGP convergence in "{}"'.format(router1.name)
 133
 134     logger.info("BGP neighbor session is up in {}".format(router1.name))
 135
 136     logger.info(
 137         "Configure tcp-mss 500 on {} and reset the session".format(router1.name)
 138     )
 139     _bgp_conf_tcp_mss(router1, "65000", "192.168.255.2")
 140     _bgp_clear_session(router1)
 141
 142     logger.info(
 143         "Configure tcp-mss 500 on {} and reset the session".format(router2.name)
 144     )
 145     _bgp_conf_tcp_mss(router2, "65001", "192.168.255.1")
 146     _bgp_clear_session(router2)
 147
 148     logger.info(
 149         "Check if neighbor session is up after reset in {}".format(router1.name)
 150     )
 151     test_func = functools.partial(_bgp_converge, router1)
 152     success, result = topotest.run_and_expect(test_func, None, count=15, wait=0.5)
 153     assert result is None, 'Failed to see BGP convergence after reset in "{}"'.format(
 154         router1.name
 155     )
 156
 157     logger.info(
 158         "Verify if TCP MSS value is synced with neighbor in {}".format(router1.name)
 159     )
 160     test_func = functools.partial(_bgp_check_neighbor_tcp_mss, router1, "192.168.255.2")
 161     success, result = topotest.run_and_expect(test_func, None, count=3, wait=0.5)
 162     assert (
 163         result is None
 164     ), 'Failed to sync TCP MSS value over BGP session in "{}"'.format(router1.name)
 165     logger.info("TCP MSS value is synced with neighbor in {}".format(router1.name))
 166
 167     logger.info(
 168         "Verify if TCP MSS value is synced with neighbor in {}".format(router2.name)
 169     )
 170     test_func = functools.partial(_bgp_check_neighbor_tcp_mss, router2, "192.168.255.1")
 171     success, result = topotest.run_and_expect(test_func, None, count=3, wait=0.5)
 172     assert (
 173         result is None
 174     ), 'Failed to sync TCP MSS value over BGP session in "{}"'.format(router2.name)
 175     logger.info("TCP MSS value is synced with neighbor in {}".format(router2.name))
 176
 177
 178 if __name__ == "__main__":
 179     args = ["-s"] + sys.argv[1:]
 180     sys.exit(pytest.main(args))