[bgpmon]Add new test case test_bgpmon

tests/bgp/templates/bgpmon.j2

@@ -0,0 +1,15 @@
+{
+    "BGP_MONITORS": {
+        "{{ peer_addr }}": {
+            "admin_status": "up",
+                "asn": "{{ asn }}",
+                "holdtime": "10",
+                "keepalive": "3",
+                "local_addr": "{{ local_addr }}",
+                "name": "{{ peer_name }}",
+                "nhopself": "0",
+                "rrclient": "0"
+        }
+    }
+}
+

tests/bgp/test_bgpmon.py

@@ -0,0 +1,153 @@
+import pytest
+import logging
+from netaddr import IPNetwork
+import ptf.testutils as testutils
+from jinja2 import Template
+import ptf.packet as scapy
+from ptf.mask import Mask
+import json
+from tests.common.fixtures.ptfhost_utils import change_mac_addresses      # lgtm[py/unused-import]
+from tests.common.fixtures.ptfhost_utils import remove_ip_addresses       # lgtm[py/unused-import]
+from tests.common.helpers.generators import generate_ips as generate_ips
+from tests.common.helpers.assertions import pytest_assert
+
+pytestmark = [
+    pytest.mark.topology('any'),
+]
+
+BGPMON_TEMPLATE_FILE = 'bgp/templates/bgpmon.j2'
+BGPMON_CONFIG_FILE = '/tmp/bgpmon.json'
+BGP_PORT = 179
+BGP_CONNECT_TIMEOUT = 121
+ZERO_ADDR = r'0.0.0.0/0'
+
+logger = logging.getLogger(__name__)
+
+def route_through_default_routes(host, ip_addr):
+    output = host.shell("show ip route {} json".format(ip_addr))['stdout']
+    routes_info = json.loads(output)
+    ret = True
+    for prefix in routes_info.keys():
+        if prefix != ZERO_ADDR:
+            ret = False
+            break
+    return ret
+
+def generate_ip_through_default_route(host):
+    # Generate an IP address routed through default routes
+    for leading in range(11, 255):
+        ip_addr = generate_ips(1, "{}.0.0.1/24".format(leading), [])[0]
+        if route_through_default_routes(host, ip_addr):
+            return ip_addr
+    return None
+
+def get_default_route_ports(host):
+    mg_facts = host.minigraph_facts(host=host.hostname)['ansible_facts']
+    route_info = json.loads(host.shell("show ip route {} json".format(ZERO_ADDR))['stdout'])
+    ports = []
+    for route in route_info[ZERO_ADDR]:
+        if route['protocol'] != 'bgp':
+            continue
+        for itfs in route['nexthops']:
+            ports.append(itfs['interfaceName'])
+    port_indices = []
+    for port in ports:
+        if 'PortChannel' in port:
+            for member in mg_facts['minigraph_portchannels'][port]['members']:
+                port_indices.append(mg_facts['minigraph_port_indices'][member])
+        else:
+            port_indices.append(mg_facts['minigraph_port_indices'][port])
+    return port_indices
+
+@pytest.fixture
+def common_setup_teardown(duthost, ptfhost):
+    peer_addr = generate_ip_through_default_route(duthost)
+    pytest_assert(peer_addr, "Failed to generate ip address for test")
+    peer_addr = str(IPNetwork(peer_addr).ip)
+    peer_ports = get_default_route_ports(duthost)
+    mg_facts = duthost.minigraph_facts(host=duthost.hostname)['ansible_facts']
+    local_addr = mg_facts['minigraph_lo_interfaces'][0]['addr']
+    # Assign peer addr to an interface on ptf
+    logger.info("Generated peer address {}".format(peer_addr))
+    bgpmon_args = {
+        'peer_addr': peer_addr,
+        'asn': mg_facts['minigraph_bgp_asn'],
+        'local_addr': local_addr,
+        'peer_name': 'bgp_monitor'
+    }
+    bgpmon_template = Template(open(BGPMON_TEMPLATE_FILE).read())
+    duthost.copy(content=bgpmon_template.render(**bgpmon_args),
+                 dest=BGPMON_CONFIG_FILE)
+    yield local_addr, peer_addr, peer_ports
+    # Cleanup bgp monitor
+    duthost.shell("redis-cli -n 4 -c DEL 'BGP_MONITORS|{}'".format(peer_addr))
+    duthost.file(path=BGPMON_CONFIG_FILE, state='absent')
+
+def build_syn_pkt(local_addr, peer_addr):
+    pkt = testutils.simple_tcp_packet(
+        pktlen=54,
+        ip_src=local_addr,
+        ip_dst=peer_addr,
+        tcp_dport=BGP_PORT,
+        tcp_flags="S"
+    )
+    exp_packet = Mask(pkt)
+    exp_packet.set_do_not_care_scapy(scapy.Ether, "dst")
+    exp_packet.set_do_not_care_scapy(scapy.Ether, "src")
+
+    exp_packet.set_do_not_care_scapy(scapy.IP, "version")
+    exp_packet.set_do_not_care_scapy(scapy.IP, "ihl")
+    exp_packet.set_do_not_care_scapy(scapy.IP, "tos")
+    exp_packet.set_do_not_care_scapy(scapy.IP, "len")
+    exp_packet.set_do_not_care_scapy(scapy.IP, "flags")
+    exp_packet.set_do_not_care_scapy(scapy.IP, "id")
+    exp_packet.set_do_not_care_scapy(scapy.IP, "frag")
+    exp_packet.set_do_not_care_scapy(scapy.IP, "ttl")
+    exp_packet.set_do_not_care_scapy(scapy.IP, "chksum")
+    exp_packet.set_do_not_care_scapy(scapy.IP, "options")
+
+    exp_packet.set_do_not_care_scapy(scapy.TCP, "sport")
+    exp_packet.set_do_not_care_scapy(scapy.TCP, "seq")
+    exp_packet.set_do_not_care_scapy(scapy.TCP, "ack")
+    exp_packet.set_do_not_care_scapy(scapy.TCP, "reserved")
+    exp_packet.set_do_not_care_scapy(scapy.TCP, "dataofs")
+    exp_packet.set_do_not_care_scapy(scapy.TCP, "window")
+    exp_packet.set_do_not_care_scapy(scapy.TCP, "chksum")
+    exp_packet.set_do_not_care_scapy(scapy.TCP, "urgptr")
+
+    exp_packet.set_ignore_extra_bytes()
+    return exp_packet
+
+def test_bgpmon(duthost, common_setup_teardown, ptfadapter):
+    """
+    Add a bgp monitor on ptf and verify that DUT is attempting to establish connection to it
+    """
+    local_addr, peer_addr, peer_ports = common_setup_teardown
+    exp_packet = build_syn_pkt(local_addr, peer_addr)
+    # Load bgp monitor config
+    logger.info("Configured bgpmon and verifying packet on {}".format(peer_ports))
+    duthost.command("sonic-cfggen -j {} -w".format(BGPMON_CONFIG_FILE))
+    # Verify syn packet on ptf
+    testutils.verify_packet_any_port(test=ptfadapter, pkt=exp_packet, ports=peer_ports, timeout=BGP_CONNECT_TIMEOUT)
+
+def test_bgpmon_no_resolve_via_default(duthost, common_setup_teardown, ptfadapter):
+    """
+    Verify no syn for BGP is sent when 'ip nht resolve-via-default' is disabled.
+    """
+    local_addr, peer_addr, peer_ports = common_setup_teardown
+    exp_packet = build_syn_pkt(local_addr, peer_addr)
+    # Load bgp monitor config
+    logger.info("Configured bgpmon and verifying no packet on {} when resolve-via-default is disabled".format(peer_ports))
+    try:
+        # Disable resolve-via-default
+        duthost.command("vtysh -c \"configure terminal\" \
+                        -c \"no ip nht resolve-via-default\"")
+        duthost.command("sonic-cfggen -j {} -w".format(BGPMON_CONFIG_FILE))
+        # Verify no syn packet is received
+        pytest_assert(0 == testutils.count_matched_packets_all_ports(test=ptfadapter, exp_packet=exp_packet, ports=peer_ports, timeout=BGP_CONNECT_TIMEOUT),
+                     "Syn packets is captured when resolve-via-default is disabled")
+    finally:
+        # Re-enable resolve-via-default
+        duthost.command("vtysh -c \"configure terminal\" \
+                        -c \"ip nht resolve-via-default\"")
+

tests/kvmtest.sh

@@ -73,7 +73,8 @@ telemetry/test_telemetry.py \
 test_features.py \
 test_procdockerstatsd.py \
 iface_namingmode/test_iface_namingmode.py \
-platform_tests/test_cpu_memory_usage.py"
+platform_tests/test_cpu_memory_usage.py \
+bgp/test_bgpmon.py"
 
 # FIXME: The lldp test has been temporarily disabled for https://github.com/Azure/sonic-mgmt/pull/2413
 # and https://github.com/Azure/sonic-buildimage/pull/5698. The reason is that these two PRs dependent on each other.