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 pytest
  39 import functools
  40
  41 # add after imports, before defining classes or functions:
  42 pytestmark = [pytest.mark.bgpd]
  43
  44 CWD = os.path.dirname(os.path.realpath(__file__))
  45 sys.path.append(os.path.join(CWD, "../"))
  46
  47 # pylint: disable=C0413
  48 from lib import topotest
  49 from lib.topogen import Topogen, TopoRouter, get_topogen
  50 from lib.topolog import logger
  51
  52 pytestmark = [pytest.mark.bgpd]
  53
  54
  55 def build_topo(tgen):
  56     for routern in range(1, 3):
  57         tgen.add_router("r{}".format(routern))
  58
  59     switch = tgen.add_switch("s1")
  60     switch.add_link(tgen.gears["r1"])
  61     switch.add_link(tgen.gears["r2"])
  62
  63
  64 def setup_module(mod):
  65     tgen = Topogen(build_topo, mod.__name__)
  66     tgen.start_topology()
  67
  68     router_list = tgen.routers()
  69
  70     for i, (rname, router) in enumerate(router_list.items(), 1):
  71         router.load_config(
  72             TopoRouter.RD_ZEBRA, os.path.join(CWD, "{}/zebra.conf".format(rname))
  73         )
  74         router.load_config(
  75             TopoRouter.RD_BGP, os.path.join(CWD, "{}/bgpd.conf".format(rname))
  76         )
  77
  78     tgen.start_router()
  79
  80
  81 def teardown_module(mod):
  82     tgen = get_topogen()
  83     tgen.stop_topology()
  84
  85
  86 def test_bgp_tcp_mss():
  87     tgen = get_topogen()
  88
  89     if tgen.routers_have_failure():
  90         pytest.skip(tgen.errors)
  91
  92     router1 = tgen.gears["r1"]
  93     router2 = tgen.gears["r2"]
  94
  95     def _bgp_converge(router):
  96         output = json.loads(router.vtysh_cmd("show ip bgp neighbor 192.168.255.2 json"))
  97         expected = {
  98             "192.168.255.2": {
  99                 "bgpState": "Established",
 100                 "addressFamilyInfo": {"ipv4Unicast": {"acceptedPrefixCounter": 0}},
 101             }
 102         }
 103         return topotest.json_cmp(output, expected)
 104
 105     def _bgp_conf_tcp_mss(router, as_num, neigh):
 106         router.vtysh_cmd(
 107             """configure terminal
 108                router bgp {0}
 109                  neighbor {1} tcp-mss 500""".format(
 110                 as_num, neigh
 111             )
 112         )
 113
 114     def _bgp_clear_session(router):
 115         router.vtysh_cmd("clear bgp *")
 116
 117     def _bgp_check_neighbor_tcp_mss(router, neigh):
 118         output = json.loads(router.vtysh_cmd("show bgp neighbor {} json".format(neigh)))
 119         expected = {
 120             "{}".format(neigh): {"bgpTcpMssConfigured": 500, "bgpTcpMssSynced": 488}
 121         }
 122         return topotest.json_cmp(output, expected)
 123
 124     logger.info("Check if neighbor sessions are up in {}".format(router1.name))
 125     test_func = functools.partial(_bgp_converge, router1)
 126     success, result = topotest.run_and_expect(test_func, None, count=15, wait=0.5)
 127     assert result is None, 'Failed to see BGP convergence in "{}"'.format(router1.name)
 128
 129     logger.info("BGP neighbor session is up in {}".format(router1.name))
 130
 131     logger.info(
 132         "Configure tcp-mss 500 on {} and reset the session".format(router1.name)
 133     )
 134     _bgp_conf_tcp_mss(router1, "65000", "192.168.255.2")
 135     _bgp_clear_session(router1)
 136
 137     logger.info(
 138         "Configure tcp-mss 500 on {} and reset the session".format(router2.name)
 139     )
 140     _bgp_conf_tcp_mss(router2, "65001", "192.168.255.1")
 141     _bgp_clear_session(router2)
 142
 143     logger.info(
 144         "Check if neighbor session is up after reset in {}".format(router1.name)
 145     )
 146     test_func = functools.partial(_bgp_converge, router1)
 147     success, result = topotest.run_and_expect(test_func, None, count=15, wait=0.5)
 148     assert result is None, 'Failed to see BGP convergence after reset in "{}"'.format(
 149         router1.name
 150     )
 151
 152     logger.info(
 153         "Verify if TCP MSS value is synced with neighbor in {}".format(router1.name)
 154     )
 155     test_func = functools.partial(_bgp_check_neighbor_tcp_mss, router1, "192.168.255.2")
 156     success, result = topotest.run_and_expect(test_func, None, count=10, wait=0.5)
 157     assert (
 158         result is None
 159     ), 'Failed to sync TCP MSS value over BGP session in "{}"'.format(router1.name)
 160     logger.info("TCP MSS value is synced with neighbor in {}".format(router1.name))
 161
 162     logger.info(
 163         "Verify if TCP MSS value is synced with neighbor in {}".format(router2.name)
 164     )
 165     test_func = functools.partial(_bgp_check_neighbor_tcp_mss, router2, "192.168.255.1")
 166     success, result = topotest.run_and_expect(test_func, None, count=10, wait=0.5)
 167     assert (
 168         result is None
 169     ), 'Failed to sync TCP MSS value over BGP session in "{}"'.format(router2.name)
 170     logger.info("TCP MSS value is synced with neighbor in {}".format(router2.name))
 171
 172
 173 if __name__ == "__main__":
 174     args = ["-s"] + sys.argv[1:]
 175     sys.exit(pytest.main(args))