tests: ospf gr helper topotests with scapy.

Testing ospf gr helper using scapy tool.

Signed-off-by: nguggarigoud <nguggarigoud@vmware.com>

tests/topotests/lib/common_config.py

@@ -34,6 +34,7 @@ import socket
 import subprocess
 import ipaddress
 import platform
+import pytest
 
 try:
     # Imports from python2
@@ -1601,7 +1602,7 @@ def find_interface_with_greater_ip(topo, router, loopback=True, interface=True):
 
 
 def write_test_header(tc_name):
-    """ Display message at beginning of test case"""
+    """Display message at beginning of test case"""
     count = 20
     logger.info("*" * (len(tc_name) + count))
     step("START -> Testcase : %s" % tc_name, reset=True)
@@ -1609,7 +1610,7 @@ def write_test_header(tc_name):
 
 
 def write_test_footer(tc_name):
-    """ Display message at end of test case"""
+    """Display message at end of test case"""
     count = 21
     logger.info("=" * (len(tc_name) + count))
     logger.info("Testcase : %s -> PASSED", tc_name)
@@ -1892,7 +1893,7 @@ def create_interfaces_cfg(tgen, topo, build=False):
                     "network",
                     "priority",
                     "cost",
-                    "mtu_ignore"
+                    "mtu_ignore",
                 ]
                 if "ospf" in data:
                     interface_data += _create_interfaces_ospf_cfg(
@@ -4591,3 +4592,64 @@ def verify_ip_nht(tgen, input_dict):
 
     logger.debug("Exiting lib API: verify_ip_nht()")
     return False
+
+
+def scapy_send_raw_packet(
+    tgen, topo, senderRouter, intf, packet=None, interval=1, count=1
+):
+    """
+    Using scapy Raw() method to send BSR raw packet from one FRR
+    to other
+
+    Parameters:
+    -----------
+    * `tgen` : Topogen object
+    * `topo` : json file data
+    * `senderRouter` : Sender router
+    * `packet` : packet in raw format
+    * `interval` : Interval between the packets
+    * `count` : Number of packets to be sent
+
+    returns:
+    --------
+    errormsg or True
+    """
+
+    global CD
+    result = ""
+    logger.debug("Entering lib API: {}".format(sys._getframe().f_code.co_name))
+    sender_interface = intf
+    rnode = tgen.routers()[senderRouter]
+
+    for destLink, data in topo["routers"][senderRouter]["links"].items():
+        if "type" in data and data["type"] == "loopback":
+            continue
+
+        if not packet:
+            packet = topo["routers"][senderRouter]["pkt"]["test_packets"][packet][
+                "data"
+            ]
+
+        if interval > 1 or count > 1:
+            cmd = (
+                "nohup /usr/bin/python {}/send_bsr_packet.py '{}' '{}' "
+                "--interval={} --count={} &".format(
+                    CD, packet, sender_interface, interval, count
+                )
+            )
+        else:
+            cmd = (
+                "/usr/bin/python {}/send_bsr_packet.py '{}' '{}' "
+                "--interval={} --count={}".format(
+                    CD, packet, sender_interface, interval, count
+                )
+            )
+
+        logger.info("Scapy cmd: \n %s", cmd)
+        result = rnode.run(cmd)
+
+        if result == "":
+            return result
+
+    logger.debug("Exiting lib API: {}".format(sys._getframe().f_code.co_name))
+    return True

tests/topotests/lib/ospf.py

@@ -28,6 +28,7 @@ from time import sleep
 from lib.topolog import logger
 from lib.topotest import frr_unicode
 from ipaddress import IPv6Address
+import sys
 
 # Import common_config to use commomnly used APIs
 from lib.common_config import (
@@ -324,8 +325,47 @@ def __create_ospf_global(
                         cmd = "no {}".format(cmd)
                     config_data.append(cmd)
 
+        # ospf gr information
+        gr_data = ospf_data.setdefault("graceful-restart", {})
+        if gr_data:
+
+            if "opaque" in gr_data and gr_data["opaque"]:
+                cmd = "capability opaque"
+                if gr_data.setdefault("delete", False):
+                    cmd = "no {}".format(cmd)
+                config_data.append(cmd)
+
+            if "helper-only" in gr_data and not gr_data["helper-only"]:
+                cmd = "graceful-restart helper-only"
+                if gr_data.setdefault("delete", False):
+                    cmd = "no {}".format(cmd)
+                config_data.append(cmd)
+            elif "helper-only" in gr_data and type(gr_data["helper-only"]) is list:
+                for rtrs in gr_data["helper-only"]:
+                    cmd = "graceful-restart helper-only {}".format(rtrs)
+                    if gr_data.setdefault("delete", False):
+                        cmd = "no {}".format(cmd)
+                    config_data.append(cmd)
+
+            if "helper" in gr_data:
+                if type(gr_data["helper"]) is not list:
+                    gr_data["helper"] = list(gr_data["helper"])
+                for helper_role in gr_data["helper"]:
+                    cmd = "graceful-restart helper {}".format(helper_role)
+                    if gr_data.setdefault("delete", False):
+                        cmd = "no {}".format(cmd)
+                    config_data.append(cmd)
+
+            if "supported-grace-time" in gr_data:
+                cmd = "graceful-restart helper supported-grace-time {}".format(
+                    gr_data["supported-grace-time"]
+                )
+                if gr_data.setdefault("delete", False):
+                    cmd = "no {}".format(cmd)
+                config_data.append(cmd)
+
         result = create_common_configuration(
-            tgen, router, config_data, ospf, build, load_config
+            tgen, router, config_data, "ospf", build, load_config
         )
 
     except InvalidCLIError:
@@ -2375,3 +2415,66 @@ def config_ospf6_interface(tgen, topo, input_dict=None, build=False, load_config
                 )
     logger.debug("Exiting lib API: {}".format(sys._getframe().f_code.co_name))
     return result
+
+@retry(retry_timeout=20)
+def verify_ospf_gr_helper(tgen, topo, dut, input_dict=None):
+    """
+    This API is used to vreify gr helper using command
+    show ip ospf graceful-restart helper
+
+    Parameters
+    ----------
+    * `tgen` : Topogen object
+    * `topo` : topology descriptions
+    * 'dut' : router
+    * 'input_dict' - values to be verified
+
+    Usage:
+    -------
+    input_dict = {
+                    "helperSupport":"Disabled",
+                    "strictLsaCheck":"Enabled",
+                    "restartSupoort":"Planned and Unplanned Restarts",
+                    "supportedGracePeriod":1800
+                }
+    result = verify_ospf_gr_helper(tgen, topo, dut, input_dict)
+
+    """
+    logger.debug("Entering lib API: {}".format(sys._getframe().f_code.co_name))
+    result = False
+
+    if 'ospf' not in topo['routers'][dut]:
+        errormsg = "[DUT: {}] OSPF is not configured on the router.".format(
+            dut)
+        return errormsg
+
+    rnode = tgen.routers()[dut]
+    logger.info("Verifying OSPF GR details on router %s:", dut)
+    show_ospf_json = run_frr_cmd(rnode, "show ip ospf graceful-restart helper json",
+                                 isjson=True)
+
+    # Verifying output dictionary show_ospf_json is empty or not
+    if not bool(show_ospf_json):
+        errormsg = "OSPF is not running"
+        raise ValueError (errormsg)
+        return errormsg
+
+    for ospf_gr, gr_data  in input_dict.items():
+        try:
+            if input_dict[ospf_gr] == show_ospf_json[ospf_gr]:
+                logger.info("[DUT: FRR] OSPF GR Helper: %s is %s", ospf_gr,
+                    show_ospf_json[ospf_gr])
+                result = True
+            else:
+                errormsg = ("[DUT: FRR] OSPF GR Helper: {} expected is {}, Found "
+                "is {}".format(ospf_gr, input_dict[ospf_gr], show_ospf_json[
+                    ospf_gr]))
+                raise ValueError (errormsg)
+                return errormsg
+
+        except KeyError:
+            errormsg = ("[DUT: FRR] OSPF GR Helper: {}".format(ospf_gr))
+            return errormsg
+
+    logger.debug("Exiting lib API: {}".format(sys._getframe().f_code.co_name))
+    return result

tests/topotests/ospf_gr_helper/ospf_gr_helper.json

@@ -0,0 +1,119 @@
+{
+    "ipv4base": "10.0.0.0",
+    "ipv4mask": 24,
+    "link_ip_start": {
+        "ipv4": "10.0.0.0",
+        "v4mask": 24
+    },
+    "lo_prefix": {
+        "ipv4": "1.0.",
+        "v4mask": 32
+    },
+    "switches": {
+        "s1": {
+            "links": {
+                "r0": {
+                    "ipv4": "17.1.1.2/24",
+                    "ospf": {
+                        "area": "0.0.0.0",
+                        "hello_interval": 1,
+                        "dead_interval": 40,
+                        "priority": 98
+                    }
+                },
+                "r1": {
+                    "ipv4": "17.1.1.1/24",
+                    "ospf": {
+                        "area": "0.0.0.0",
+                        "hello_interval": 1,
+                        "dead_interval": 40,
+                        "priority": 99
+                    }
+                },
+                "r2": {
+                    "ipv4": "17.1.1.3/24",
+                    "ospf": {
+                        "area": "0.0.0.0",
+                        "hello_interval": 1,
+                        "dead_interval": 40,
+                        "priority": 0
+                    }
+                },
+                "r3": {
+                    "ipv4": "17.1.1.4/24",
+                    "ospf": {
+                        "area": "0.0.0.0",
+                        "hello_interval": 1,
+                        "dead_interval": 40,
+                        "priority": 0
+                    }
+                }
+            }
+        }
+    },
+    "routers": {
+        "r0": {
+            "links": {
+                "lo": {
+                    "ipv4": "auto",
+                    "type": "loopback"
+                }
+            },
+            "ospf": {
+                "router_id": "100.1.1.0",
+                "neighbors": {
+                    "r1": {},
+                    "r2": {},
+                    "r3": {}
+                }
+            }
+        },
+        "r1": {
+            "links": {
+                "lo": {
+                    "ipv4": "auto",
+                    "type": "loopback"
+                }
+            },
+            "ospf": {
+                "router_id": "1.1.1.1",
+                "neighbors": {
+                    "r0": {},
+                    "r2": {},
+                    "r3": {}
+                }
+            },
+            "opq_lsa_hex": "01005e00000570708bd051ef080045c0005cc18b0000015904f711010101e00000050204004801010101000000001e8d0000000000000000000000000001000102090300000001010101800000013bd1002c000100040000070800020001010000000003000411010101"
+        },
+        "r2": {
+            "links": {
+                "lo": {
+                    "ipv4": "auto",
+                    "type": "loopback"
+                }
+            },
+            "ospf": {
+                "router_id": "100.1.1.2",
+                "neighbors": {
+                    "r1": {},
+                    "r0": {}
+                }
+            }
+        },
+        "r3": {
+            "links": {
+                "lo": {
+                    "ipv4": "auto",
+                    "type": "loopback"
+                }
+            },
+            "ospf": {
+                "router_id": "100.1.1.3",
+                "neighbors": {
+                    "r0": {},
+                    "r1": {}
+                }
+            }
+        }
+    }
+}

tests/topotests/ospf_gr_helper/test_ospf_gr_helper.py

@@ -0,0 +1,752 @@
+#!/usr/bin/python
+
+#
+# Copyright (c) 2021 by VMware, Inc. ("VMware")
+# Used Copyright (c) 2018 by Network Device Education Foundation, Inc.
+# ("NetDEF") in this file.
+#
+# 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 VMWARE DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL VMWARE 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.
+#
+
+
+"""OSPF Basic Functionality Automation."""
+import os
+import sys
+import time
+import pytest
+import json
+from time import sleep
+from copy import deepcopy
+import ipaddress
+
+# Save the Current Working Directory to find configuration files.
+CWD = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(os.path.join(CWD, "../"))
+
+# pylint: disable=C0413
+# Import topogen and topotest helpers
+from mininet.topo import Topo
+from lib.topogen import Topogen, get_topogen
+
+# Import topoJson from lib, to create topology and initial configuration
+from lib.common_config import (
+    start_topology,
+    write_test_header,
+    write_test_footer,
+    reset_config_on_routers,
+    verify_rib,
+    create_static_routes,
+    step,
+    create_route_maps,
+    shutdown_bringup_interface,
+    create_interfaces_cfg,
+    topo_daemons,
+    scapy_send_raw_packet
+)
+
+from lib.topolog import logger
+from lib.topojson import build_topo_from_json, build_config_from_json
+
+from lib.ospf import (
+    verify_ospf_neighbor,
+    clear_ospf,
+    verify_ospf_gr_helper,
+    create_router_ospf,
+    verify_ospf_interface,
+    verify_ospf_database,
+)
+
+# Global variables
+topo = None
+Iters = 5
+sw_name = None
+intf = None
+intf1 = None
+pkt = None
+
+# Reading the data from JSON File for topology creation
+jsonFile = "{}/ospf_gr_helper.json".format(CWD)
+try:
+    with open(jsonFile, "r") as topoJson:
+        topo = json.load(topoJson)
+except IOError:
+    assert False, "Could not read file {}".format(jsonFile)
+
+"""
+Topology:
+
+      Please view in a fixed-width font such as Courier.
+      Topo : Broadcast Networks
+      DUT - HR      RR
+        +---+       +---+          +---+           +---+
+        |R0 +       +R1 +          +R2 +           +R3 |
+        +-+-+       +-+-+          +-+-+           +-+-+
+          |           |              |               |
+          |           |              |               |
+        --+-----------+--------------+---------------+-----
+                         Ethernet Segment
+
+Testcases:
+
+TC1.    Verify by default helper support is disabled for FRR ospf
+TC2.    OSPF GR on Broadcast : Verify DUT enters Helper mode when neighbor
+        sends grace lsa, helps RR to restart gracefully (RR = DR)
+TC3.    OSPF GR on Broadcast : Verify DUT enters Helper mode when neighbor
+        sends grace lsa, helps RR to restart gracefully (RR = BDR)
+TC4.    OSPF GR on Broadcast : Verify DUT enters Helper mode when neighbor
+        sends grace lsa, helps RR to restart gracefully (RR = DRother)
+TC5.    OSPF GR on P2P : Verify DUT enters Helper mode when neighbor sends
+        grace lsa, helps RR to restart gracefully.
+TC6.    Verify all the show commands newly introducted as part of ospf
+        helper support - Json Key verification wrt to show commands.
+TC7.    Verify helper when grace lsa is received with different configured
+        value in process level (higher, lower, grace lsa timer above 1800)
+TC8.    Verify helper functionality when dut is helping RR and new grace lsa
+        is received from RR.
+"""
+
+
+class CreateTopo(Topo):
+    """
+    Test topology builder.
+
+    * `Topo`: Topology object
+    """
+
+    def build(self, *_args, **_opts):
+        """Build function."""
+        tgen = get_topogen(self)
+
+        # Building topology from json file
+        build_topo_from_json(tgen, topo)
+
+
+def setup_module(mod):
+    """
+    Sets up the pytest environment
+
+    * `mod`: module name
+    """
+    global topo, intf, intf1, sw_name, pkt
+    testsuite_run_time = time.asctime(time.localtime(time.time()))
+    logger.info("Testsuite start time: {}".format(testsuite_run_time))
+    logger.info("=" * 40)
+
+    logger.info("Running setup_module to create topology")
+
+    # This function initiates the topology build with Topogen...
+    tgen = Topogen(CreateTopo, mod.__name__)
+    # ... and here it calls Mininet initialization functions.
+
+    # get list of daemons needs to be started for this suite.
+    daemons = topo_daemons(tgen, topo)
+
+    # Starting topology, create tmp files which are loaded to routers
+    #  to start deamons and then start routers
+    start_topology(tgen, daemons)
+
+    # Creating configuration from JSON
+    build_config_from_json(tgen, topo)
+
+    # Don't run this test if we have any failure.
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    ospf_covergence = verify_ospf_neighbor(tgen, topo, lan=True)
+    assert ospf_covergence is True, "setup_module :Failed \n Error:" " {}".format(
+        ospf_covergence
+    )
+
+    sw_name = topo["switches"].keys()[0]
+    intf = topo["routers"]["r0"]["links"][sw_name]["interface"]
+    intf1 = topo["routers"]["r1"]["links"][sw_name]["interface"]
+    pkt = topo["routers"]["r1"]["opq_lsa_hex"]
+
+    logger.info("Running setup_module() done")
+
+
+def teardown_module():
+    """Teardown the pytest environment"""
+
+    logger.info("Running teardown_module to delete topology")
+
+    tgen = get_topogen()
+
+    try:
+        # Stop toplogy and Remove tmp files
+        tgen.stop_topology
+
+    except OSError:
+        # OSError exception is raised when mininet tries to stop switch
+        # though switch is stopped once but mininet tries to stop same
+        # switch again, where it ended up with exception
+        pass
+
+
+def delete_ospf():
+    """delete ospf process after each test"""
+    tgen = get_topogen()
+    step("Delete ospf process")
+    for rtr in topo["routers"]:
+        ospf_del = {rtr: {"ospf": {"delete": True}}}
+        result = create_router_ospf(tgen, topo, ospf_del)
+        assert result is True, "Testcase: Failed \n Error: {}".format(result)
+
+
+# ##################################
+# Test cases start here.
+# ##################################
+
+
+def test_ospf_gr_helper_tc1_p0(request):
+    """Verify by default helper support is disabled for FRR ospf"""
+
+    tc_name = request.node.name
+    write_test_header(tc_name)
+    tgen = get_topogen()
+
+    # Don't run this test if we have any failure.
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    global topo, intf, intf1, pkt
+
+    step("Bring up the base config as per the topology")
+    reset_config_on_routers(tgen)
+    ospf_covergence = verify_ospf_neighbor(tgen, topo, lan=True)
+    assert (
+        ospf_covergence is True
+    ), "OSPF is not after reset config \n Error:" " {}".format(ospf_covergence)
+
+    step("Verify that GR helper route is disabled by default to the in" "the DUT.")
+    input_dict = {
+        "helperSupport": "Disabled",
+        "strictLsaCheck": "Enabled",
+        "restartSupoort": "Planned and Unplanned Restarts",
+        "supportedGracePeriod": 1800,
+    }
+    dut = "r0"
+    result = verify_ospf_gr_helper(tgen, topo, dut, input_dict)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    step("Verify that DUT does not enter helper mode upon receiving the " "grace lsa.")
+
+    # send grace lsa
+    scapy_send_raw_packet(tgen, topo, "r1", intf1, pkt)
+
+    input_dict = {"activeRestarterCnt": 1}
+    dut = "r0"
+    result = verify_ospf_gr_helper(tgen, topo, dut, input_dict, expected=False)
+    assert (
+        result is not True
+    ), "Testcase {} : Failed. DUT entered helper role " " \n Error: {}".format(
+        tc_name, result
+    )
+
+    step("Configure graceful restart in the DUT")
+    ospf_gr_r0 = {
+        "r0": {"ospf": {"graceful-restart": {"helper-only": [], "opaque": True}}}
+    }
+    result = create_router_ospf(tgen, topo, ospf_gr_r0)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    step("Verify that GR helper route is enabled in the DUT.")
+    input_dict = {
+        "helperSupport": "Enabled",
+        "strictLsaCheck": "Enabled",
+        "restartSupoort": "Planned and Unplanned Restarts",
+        "supportedGracePeriod": 1800,
+    }
+    dut = "r0"
+    result = verify_ospf_gr_helper(tgen, topo, dut, input_dict)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    ospf_gr_r1 = {
+        "r1": {"ospf": {"graceful-restart": {"helper-only": [], "opaque": True}}}
+    }
+    result = create_router_ospf(tgen, topo, ospf_gr_r1)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    step("Perform GR in RR.")
+    step("Verify that DUT does enter helper mode upon receiving" " the grace lsa.")
+    input_dict = {"activeRestarterCnt": 1}
+    gracelsa_sent = False
+    repeat = 0
+    dut = "r0"
+    while not gracelsa_sent and repeat < Iters:
+        gracelsa_sent = scapy_send_raw_packet(tgen, topo, "r1", intf1, pkt)
+        result = verify_ospf_gr_helper(tgen, topo, dut, input_dict)
+        if isinstance(result, str):
+            repeat += 1
+            gracelsa_sent = False
+
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    step("Unconfigure the GR helper command.")
+    ospf_gr_r0 = {
+        "r0": {
+            "ospf": {
+                "graceful-restart": {"helper-only": [], "opaque": True, "delete": True}
+            }
+        }
+    }
+    result = create_router_ospf(tgen, topo, ospf_gr_r0)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    input_dict = {"helperSupport": "Disabled"}
+    dut = "r0"
+    result = verify_ospf_gr_helper(tgen, topo, dut, input_dict)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    step("Configure gr helper using the router id")
+    ospf_gr_r0 = {
+        "r0": {
+            "ospf": {"graceful-restart": {"helper-only": ["1.1.1.1"], "opaque": True}}
+        }
+    }
+    result = create_router_ospf(tgen, topo, ospf_gr_r0)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    step("Verify that DUT does enter helper mode upon receiving" " the grace lsa.")
+    input_dict = {"activeRestarterCnt": 1}
+    gracelsa_sent = False
+    repeat = 0
+    dut = "r0"
+    while not gracelsa_sent and repeat < Iters:
+        gracelsa_sent = scapy_send_raw_packet(tgen, topo, "r1", intf1, pkt)
+        result = verify_ospf_gr_helper(tgen, topo, dut, input_dict)
+        if isinstance(result, str):
+            repeat += 1
+            gracelsa_sent = False
+
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    step("Un Configure gr helper using the router id")
+    ospf_gr_r0 = {
+        "r0": {
+            "ospf": {
+                "graceful-restart": {
+                    "helper-only": ["1.1.1.1"],
+                    "opaque": True,
+                    "delete": True,
+                }
+            }
+        }
+    }
+    result = create_router_ospf(tgen, topo, ospf_gr_r0)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    step("Verify that GR helper router is disabled in the DUT for" " router id x.x.x.x")
+    input_dict = {"enabledRouterIds": [{"routerId": "1.1.1.1"}]}
+    dut = "r0"
+    result = verify_ospf_gr_helper(tgen, topo, dut, input_dict, expected=False)
+    assert (
+        result is not True
+    ), "Testcase {} : Failed, Helper role enabled for RR\n Error: {}".format(
+        tc_name, result
+    )
+    delete_ospf()
+    write_test_footer(tc_name)
+
+
+def test_ospf_gr_helper_tc2_p0(request):
+    """
+    OSPF GR on Broadcast : Verify DUT enters Helper mode when neighbor
+    sends grace lsa, helps RR to restart gracefully (RR = DR)
+    """
+    tc_name = request.node.name
+    write_test_header(tc_name)
+    tgen = get_topogen()
+
+    # Don't run this test if we have any failure.
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    global topo, intf, intf1, pkt
+
+    step("Bring up the base config as per the topology")
+    step(
+        "Configure DR priority as 99 in RR , DUT dr priority = 98 "
+        "& reset ospf process in all the routers"
+    )
+    reset_config_on_routers(tgen)
+    ospf_covergence = verify_ospf_neighbor(tgen, topo, lan=True)
+    assert (
+        ospf_covergence is True
+    ), "OSPF is not after reset config \n Error:" " {}".format(ospf_covergence)
+    ospf_gr_r0 = {
+        "r0": {"ospf": {"graceful-restart": {"helper-only": [], "opaque": True}}}
+    }
+    result = create_router_ospf(tgen, topo, ospf_gr_r0)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    ospf_gr_r1 = {
+        "r1": {"ospf": {"graceful-restart": {"helper-only": [], "opaque": True}}}
+    }
+    result = create_router_ospf(tgen, topo, ospf_gr_r1)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    step("Verify that DUT enters into helper mode.")
+
+    input_dict = {"activeRestarterCnt": 1}
+    gracelsa_sent = False
+    repeat = 0
+    dut = "r0"
+    while not gracelsa_sent and repeat < Iters:
+        gracelsa_sent = scapy_send_raw_packet(tgen, topo, "r1", intf1, pkt)
+        result = verify_ospf_gr_helper(tgen, topo, dut, input_dict)
+        if isinstance(result, str):
+            repeat += 1
+            gracelsa_sent = False
+
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    delete_ospf()
+    write_test_footer(tc_name)
+
+
+def test_ospf_gr_helper_tc3_p1(request):
+    """
+    OSPF GR on Broadcast : Verify DUT enters Helper mode when neighbor
+    sends grace lsa, helps RR to restart gracefully (RR = BDR)
+    """
+    tc_name = request.node.name
+    write_test_header(tc_name)
+    tgen = get_topogen()
+
+    # Don't run this test if we have any failure.
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    global topo, intf, intf1, pkt
+
+    step("Bring up the base config as per the topology")
+    step(
+        "Configure DR priority as 99 in RR , DUT dr priority = 98 "
+        "& reset ospf process in all the routers"
+    )
+    reset_config_on_routers(tgen)
+    ospf_covergence = verify_ospf_neighbor(tgen, topo, lan=True)
+    assert (
+        ospf_covergence is True
+    ), "OSPF is not after reset config \n Error:" " {}".format(ospf_covergence)
+    step(
+        "Configure DR pririty 100 on R0 and clear ospf neighbors " "on all the routers."
+    )
+
+    input_dict = {
+        "r0": {
+            "links": {
+                sw_name: {
+                    "interface": topo["routers"]["r0"]["links"][sw_name]["interface"],
+                    "ospf": {"priority": 100},
+                }
+            }
+        }
+    }
+
+    result = create_interfaces_cfg(tgen, input_dict)
+    assert result is True, "Testcase {} :Failed \n Error: {}".format(tc_name, result)
+
+    step("Clear ospf neighbours in all routers")
+    for rtr in topo["routers"]:
+        clear_ospf(tgen, rtr)
+
+    step("Verify that DR election is triggered and R0 is elected as DR")
+    input_dict = {
+        "r0": {
+            "ospf": {
+                "neighbors": {
+                    "r1": {"state": "Full", "role": "Backup"},
+                    "r2": {"state": "Full", "role": "DROther"},
+                    "r3": {"state": "Full", "role": "DROther"},
+                }
+            }
+        }
+    }
+    dut = "r0"
+    result = verify_ospf_neighbor(tgen, topo, dut, input_dict, lan=True)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    ospf_gr_r0 = {
+        "r0": {"ospf": {"graceful-restart": {"helper-only": [], "opaque": True}}}
+    }
+    result = create_router_ospf(tgen, topo, ospf_gr_r0)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    ospf_gr_r1 = {
+        "r1": {"ospf": {"graceful-restart": {"helper-only": [], "opaque": True}}}
+    }
+    result = create_router_ospf(tgen, topo, ospf_gr_r1)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    step("Verify that DUT enters into helper mode.")
+
+    input_dict = {"activeRestarterCnt": 1}
+    gracelsa_sent = False
+    repeat = 0
+    dut = "r0"
+    while not gracelsa_sent and repeat < Iters:
+        gracelsa_sent = scapy_send_raw_packet(tgen, topo, "r1", intf1, pkt)
+        result = verify_ospf_gr_helper(tgen, topo, dut, input_dict)
+        if isinstance(result, str):
+            repeat += 1
+            gracelsa_sent = False
+
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    delete_ospf()
+    write_test_footer(tc_name)
+
+
+def test_ospf_gr_helper_tc4_p1(request):
+    """
+    OSPF GR on Broadcast : Verify DUT enters Helper mode when neighbor
+    sends grace lsa, helps RR to restart gracefully (RR = DRother)
+    """
+    tc_name = request.node.name
+    write_test_header(tc_name)
+    tgen = get_topogen()
+
+    # Don't run this test if we have any failure.
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    global topo, intf, intf1, pkt
+
+    step("Bring up the base config as per the topology")
+    step(
+        "Configure DR priority as 99 in RR , DUT dr priority = 98 "
+        "& reset ospf process in all the routers"
+    )
+    reset_config_on_routers(tgen)
+    ospf_covergence = verify_ospf_neighbor(tgen, topo, lan=True)
+    assert (
+        ospf_covergence is True
+    ), "OSPF is not after reset config \n Error:" " {}".format(ospf_covergence)
+    step(
+        "Configure DR pririty 100 on R0 and clear ospf neighbors " "on all the routers."
+    )
+
+    input_dict = {
+        "r0": {
+            "links": {
+                sw_name: {
+                    "interface": topo["routers"]["r0"]["links"][sw_name]["interface"],
+                    "ospf": {"priority": 0},
+                }
+            }
+        }
+    }
+
+    result = create_interfaces_cfg(tgen, input_dict)
+    assert result is True, "Testcase {} :Failed \n Error: {}".format(tc_name, result)
+
+    step("Clear ospf neighbours in all routers")
+    for rtr in topo["routers"]:
+        clear_ospf(tgen, rtr)
+
+    step("Verify that DR election is triggered and R0 is elected as 2-Way")
+    input_dict = {
+        "r0": {
+            "ospf": {
+                "neighbors": {
+                    "r1": {"state": "Full", "role": "DR"},
+                    "r2": {"state": "2-Way", "role": "DROther"},
+                    "r3": {"state": "2-Way", "role": "DROther"},
+                }
+            }
+        }
+    }
+    dut = "r0"
+    result = verify_ospf_neighbor(tgen, topo, dut, input_dict, lan=True)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    ospf_gr_r0 = {
+        "r0": {"ospf": {"graceful-restart": {"helper-only": [], "opaque": True}}}
+    }
+    result = create_router_ospf(tgen, topo, ospf_gr_r0)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    ospf_gr_r1 = {
+        "r1": {"ospf": {"graceful-restart": {"helper-only": [], "opaque": True}}}
+    }
+    result = create_router_ospf(tgen, topo, ospf_gr_r1)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    step("Verify that DUT enters into helper mode.")
+
+    input_dict = {"activeRestarterCnt": 1}
+    gracelsa_sent = False
+    repeat = 0
+    dut = "r0"
+    while not gracelsa_sent and repeat < Iters:
+        gracelsa_sent = scapy_send_raw_packet(tgen, topo, "r1", intf1, pkt)
+        result = verify_ospf_gr_helper(tgen, topo, dut, input_dict)
+        if isinstance(result, str):
+            repeat += 1
+            gracelsa_sent = False
+
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    delete_ospf()
+
+    write_test_footer(tc_name)
+
+
+def test_ospf_gr_helper_tc7_p1(request):
+    """
+    Test ospf gr helper
+    Verify helper when grace lsa is received with different configured
+    value in process level (higher, lower, grace lsa timer above 1800)
+    """
+    tc_name = request.node.name
+    write_test_header(tc_name)
+    tgen = get_topogen()
+
+    # Don't run this test if we have any failure.
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    global topo, intf, intf1, pkt
+
+    step("Bring up the base config as per the topology")
+    step(
+        "Configure DR priority as 99 in RR , DUT dr priority = 98 "
+        "& reset ospf process in all the routers"
+    )
+    step(
+        "Enable GR on RR and DUT with grace period on RR = 333"
+        "and grace period on DUT = 300"
+    )
+    reset_config_on_routers(tgen)
+    ospf_covergence = verify_ospf_neighbor(tgen, topo, lan=True)
+    assert (
+        ospf_covergence is True
+    ), "OSPF is not after reset config \n Error:" " {}".format(ospf_covergence)
+    ospf_gr_r0 = {
+        "r0": {"ospf": {"graceful-restart": {"helper-only": [], "opaque": True}}}
+    }
+    result = create_router_ospf(tgen, topo, ospf_gr_r0)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    ospf_gr_r1 = {
+        "r1": {"ospf": {"graceful-restart": {"helper-only": [], "opaque": True}}}
+    }
+    result = create_router_ospf(tgen, topo, ospf_gr_r1)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    input_dict = {"supportedGracePeriod": 1800}
+    dut = "r0"
+    result = verify_ospf_gr_helper(tgen, topo, dut, input_dict)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    step("Configure grace period = 1801 on RR and restart ospf .")
+    grace_period_1801 = "01005e00000570708bd051ef080045c0005cbeb10000015907d111010101e00000050204004801010101000000009714000000000000000000000000000100010209030000000101010180000001c8e9002c000100040000016800020001010000000003000411010101"
+    gracelsa_sent = scapy_send_raw_packet(tgen, topo, "r1", intf1, grace_period_1801)
+
+    step("Verify R0 does not enter helper mode.")
+    input_dict = {"activeRestarterCnt": 1}
+    dut = "r0"
+    result = verify_ospf_gr_helper(tgen, topo, dut, input_dict, expected=False)
+    assert (
+        result is not True
+    ), "Testcase {} : Failed. DUT entered helper role " " \n Error: {}".format(
+        tc_name, result
+    )
+
+    delete_ospf()
+
+    write_test_footer(tc_name)
+
+
+def test_ospf_gr_helper_tc8_p1(request):
+    """
+    Test ospf gr helper
+
+    Verify helper functionality when dut is helping RR and new grace lsa
+    is received from RR.
+    """
+    tc_name = request.node.name
+    write_test_header(tc_name)
+    tgen = get_topogen()
+
+    # Don't run this test if we have any failure.
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    global topo, intf, intf1, pkt
+
+    step("Bring up the base config as per the topology")
+    step("Enable GR")
+    reset_config_on_routers(tgen)
+    ospf_covergence = verify_ospf_neighbor(tgen, topo, lan=True)
+    assert (
+        ospf_covergence is True
+    ), "OSPF is not after reset config \n Error:" " {}".format(ospf_covergence)
+    ospf_gr_r0 = {
+        "r0": {"ospf": {"graceful-restart": {"helper-only": [], "opaque": True}}}
+    }
+    result = create_router_ospf(tgen, topo, ospf_gr_r0)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    ospf_gr_r1 = {
+        "r1": {"ospf": {"graceful-restart": {"helper-only": [], "opaque": True}}}
+    }
+    result = create_router_ospf(tgen, topo, ospf_gr_r1)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    input_dict = {"supportedGracePeriod": 1800}
+    dut = "r0"
+    result = verify_ospf_gr_helper(tgen, topo, dut, input_dict)
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    step("Verify that DUT enters into helper mode.")
+
+    input_dict = {"activeRestarterCnt": 1}
+    gracelsa_sent = False
+    repeat = 0
+    dut = "r0"
+    while not gracelsa_sent and repeat < Iters:
+        gracelsa_sent = scapy_send_raw_packet(tgen, topo, "r1", intf1, pkt)
+        result = verify_ospf_gr_helper(tgen, topo, dut, input_dict)
+        if isinstance(result, str):
+            repeat += 1
+            gracelsa_sent = False
+
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    step("Send the Grace LSA again to DUT when RR is in GR.")
+    input_dict = {"activeRestarterCnt": 1}
+    gracelsa_sent = False
+    repeat = 0
+    dut = "r0"
+    while not gracelsa_sent and repeat < Iters:
+        gracelsa_sent = scapy_send_raw_packet(tgen, topo, "r1", intf1, pkt)
+        result = verify_ospf_gr_helper(tgen, topo, dut, input_dict)
+        if isinstance(result, str):
+            repeat += 1
+            gracelsa_sent = False
+
+    assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result)
+
+    delete_ospf()
+
+    write_test_footer(tc_name)
+
+
+if __name__ == "__main__":
+    args = ["-s"] + sys.argv[1:]
+    sys.exit(pytest.main(args))