Merge pull request #8564 from rameshabhinay/bgp_tcp_mss

bgpd: Support tcp-mss for bgp neighbors

1 files changed, 178 insertions, 0 deletions

diff --git a/tests/topotests/bgp_tcp_mss/test_bgp_tcp_mss.py b/tests/topotests/bgp_tcp_mss/test_bgp_tcp_mss.py
new file mode 100644
index 0000000000..7500c3b3ad
--- /dev/null
+++ b/tests/topotests/bgp_tcp_mss/test_bgp_tcp_mss.py
@@ -0,0 +1,178 @@
+#!/usr/bin/env python
+
+#
+# bgp_tcp_mss.py
+# Part of NetDEF Topology Tests
+#
+# Copyright (c) 2021 by
+# Abhinay Ramesh <rabhinay@vmware.com>
+#
+# Permission to use, copy, modify, and/or distribute this software
+# for any purpose with or without fee is hereby granted, provided
+# that the above copyright notice and this permission notice appear
+# in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NETDEF DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NETDEF BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY
+# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+# OF THIS SOFTWARE.
+#
+
+"""
+bgp_tcp_mss.py:
+
+Test if works the following commands:
+router bgp 65000
+  neighbor 192.168.255.2 tcp-mss 500
+
+Need to verify if the tcp-mss value is reflected in the TCP session.
+"""
+
+import os
+import sys
+import json
+import time
+import pytest
+import functools
+
+# add after imports, before defining classes or functions:
+pytestmark = [pytest.mark.bgpd]
+
+CWD = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(os.path.join(CWD, "../"))
+
+# pylint: disable=C0413
+from lib import topotest
+from lib.topogen import Topogen, TopoRouter, get_topogen
+from lib.topolog import logger
+from mininet.topo import Topo
+
+
+class TemplateTopo(Topo):
+    def build(self, *_args, **_opts):
+        tgen = get_topogen(self)
+
+        for routern in range(1, 3):
+            tgen.add_router("r{}".format(routern))
+
+        switch = tgen.add_switch("s1")
+        switch.add_link(tgen.gears["r1"])
+        switch.add_link(tgen.gears["r2"])
+
+
+def setup_module(mod):
+    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen.start_topology()
+
+    router_list = tgen.routers()
+
+    for i, (rname, router) in enumerate(router_list.items(), 1):
+        router.load_config(
+            TopoRouter.RD_ZEBRA, os.path.join(CWD, "{}/zebra.conf".format(rname))
+        )
+        router.load_config(
+            TopoRouter.RD_BGP, os.path.join(CWD, "{}/bgpd.conf".format(rname))
+        )
+
+    tgen.start_router()
+
+
+def teardown_module(mod):
+    tgen = get_topogen()
+    tgen.stop_topology()
+
+
+def test_bgp_tcp_mss():
+    tgen = get_topogen()
+
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    router1 = tgen.gears["r1"]
+    router2 = tgen.gears["r2"]
+
+    def _bgp_converge(router):
+        output = json.loads(router.vtysh_cmd("show ip bgp neighbor 192.168.255.2 json"))
+        expected = {
+            "192.168.255.2": {
+                "bgpState": "Established",
+                "addressFamilyInfo": {"ipv4Unicast": {"acceptedPrefixCounter": 0}},
+            }
+        }
+        return topotest.json_cmp(output, expected)
+
+    def _bgp_conf_tcp_mss(router, as_num, neigh):
+        router.vtysh_cmd(
+            """configure terminal
+               router bgp {0}
+                 neighbor {1} tcp-mss 500""".format(
+                as_num, neigh
+            )
+        )
+
+    def _bgp_clear_session(router):
+        router.vtysh_cmd("clear bgp *")
+
+    def _bgp_check_neighbor_tcp_mss(router, neigh):
+        output = json.loads(router.vtysh_cmd("show bgp neighbor {} json".format(neigh)))
+        expected = {
+            "{}".format(neigh): {"bgpTcpMssConfigured": 500, "bgpTcpMssSynced": 488}
+        }
+        return topotest.json_cmp(output, expected)
+
+    logger.info("Check if neighbor sessions are up in {}".format(router1.name))
+    test_func = functools.partial(_bgp_converge, router1)
+    success, result = topotest.run_and_expect(test_func, None, count=15, wait=0.5)
+    assert result is None, 'Failed to see BGP convergence in "{}"'.format(router1.name)
+
+    logger.info("BGP neighbor session is up in {}".format(router1.name))
+
+    logger.info(
+        "Configure tcp-mss 500 on {} and reset the session".format(router1.name)
+    )
+    _bgp_conf_tcp_mss(router1, "65000", "192.168.255.2")
+    _bgp_clear_session(router1)
+
+    logger.info(
+        "Configure tcp-mss 500 on {} and reset the session".format(router2.name)
+    )
+    _bgp_conf_tcp_mss(router2, "65001", "192.168.255.1")
+    _bgp_clear_session(router2)
+
+    logger.info(
+        "Check if neighbor session is up after reset in {}".format(router1.name)
+    )
+    test_func = functools.partial(_bgp_converge, router1)
+    success, result = topotest.run_and_expect(test_func, None, count=15, wait=0.5)
+    assert result is None, 'Failed to see BGP convergence after reset in "{}"'.format(
+        router1.name
+    )
+
+    logger.info(
+        "Verify if TCP MSS value is synced with neighbor in {}".format(router1.name)
+    )
+    test_func = functools.partial(_bgp_check_neighbor_tcp_mss, router1, "192.168.255.2")
+    success, result = topotest.run_and_expect(test_func, None, count=3, wait=0.5)
+    assert (
+        result is None
+    ), 'Failed to sync TCP MSS value over BGP session in "{}"'.format(router1.name)
+    logger.info("TCP MSS value is synced with neighbor in {}".format(router1.name))
+
+    logger.info(
+        "Verify if TCP MSS value is synced with neighbor in {}".format(router2.name)
+    )
+    test_func = functools.partial(_bgp_check_neighbor_tcp_mss, router2, "192.168.255.1")
+    success, result = topotest.run_and_expect(test_func, None, count=3, wait=0.5)
+    assert (
+        result is None
+    ), 'Failed to sync TCP MSS value over BGP session in "{}"'.format(router2.name)
+    logger.info("TCP MSS value is synced with neighbor in {}".format(router2.name))
+
+
+if __name__ == "__main__":
+    args = ["-s"] + sys.argv[1:]
+    sys.exit(pytest.main(args))