[dualtor] Add server traffic utility

[lolyu]

Add server traffic utility to check the traffic between the selected ToR
and the server.

Signed-off-by: Longxiang Lyu [email protected]

Description of PR

Summary:
Fixes #2805

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• Test case(new/improvement)

Approach

What is the motivation for this PR?

Add util to verify the traffic between ToR and servers.

How did you do it?

Add a context manager class to dump the traffic between ToR and server(from the vlan interface on vm host server) and
check if there are expected packets out of captured packets.

How did you verify/test it?

• demo testcase

import logging
import pytest
import random
import time

from scapy.all import IP, Ether
from ptf import testutils, mask
from tests.common.dualtor.dual_tor_mock import *
from tests.common.dualtor.tunnel_traffic_utils import tunnel_traffic_monitor
from tests.common.dualtor.dual_tor_utils import get_t1_ptf_ports, rand_selected_interface, flush_neighbor
from tests.common.dualtor.server_traffic_utils import ServerTrafficMonitor


pytestmark = [
    pytest.mark.topology("t0")
]


@pytest.fixture(scope="function")
def build_packet_to_server(rand_selected_interface, ptfadapter, rand_selected_dut, tunnel_traffic_monitor):
    """Build packet destinated to server selected by test_interface."""
    tor = rand_selected_dut
    _, server_details = rand_selected_interface
    server_ipv4 = server_details["server_ipv4"].split("/")[0]
    pkt_dscp = random.choice(range(0, 33))
    pkt_ttl = random.choice(range(3, 65))
    pkt = testutils.simple_ip_packet(
        eth_dst=tor.facts["router_mac"],
        eth_src=ptfadapter.dataplane.get_mac(0, 0),
        ip_src="1.1.1.1",
        ip_dst=server_ipv4,
        ip_dscp=pkt_dscp,
        ip_ttl=pkt_ttl
    )
    logging.info("the packet destinated to server %s:\n%s", server_ipv4, tunnel_traffic_monitor._dump_show_str(pkt))
    return pkt


@pytest.fixture(scope="function")
def stop_garp_service(ptfhost):
    ptfhost.shell("supervisorctl stop garp_service")
    yield
    ptfhost.shell("supervisorctl start garp_service")


def test_standby_tor_remove_neighbor_downstream_standby(
    apply_mock_dual_tor_tables,
    apply_mock_dual_tor_kernel_configs,
    apply_standby_state_to_orchagent,
    conn_graph_facts, tbinfo,
    build_packet_to_server, rand_selected_interface, ptfadapter,
    rand_selected_dut, tunnel_traffic_monitor, vmhost,
    stop_garp_service, rand_unselected_dut
):

    def build_exp_pkt(packet):
        exp_pkt = mask.Mask(packet)
        exp_pkt.set_do_not_care_scapy(Ether, "dst")
        exp_pkt.set_do_not_care_scapy(Ether, "src")
        exp_pkt.set_do_not_care_scapy(IP, "tos")
        exp_pkt.set_do_not_care_scapy(IP, "ttl")
        exp_pkt.set_do_not_care_scapy(IP, "chksum")
        return exp_pkt

    tor = rand_selected_dut
    tor = rand_unselected_dut
    pkt = build_packet_to_server
    iface, server_details = rand_selected_interface
    server_ipv4 = server_details["server_ipv4"].split("/")[0]

    exp_pkt = build_exp_pkt(pkt)

    ptfadapter.before_send = lambda *args, **kwargs: time.sleep(0.5)

    ptf_t1_intf = random.choice(get_t1_ptf_ports(tor, tbinfo))
    logging.info("send traffic to server %s from ptf t1 interface %s", server_ipv4, ptf_t1_intf)
    with flush_neighbor(tor, server_ipv4):
        with tunnel_traffic_monitor(tor, existing=False):
            with ServerTrafficMonitor(tor, vmhost, iface, conn_graph_facts, exp_pkt, existing=False):
                testutils.send(ptfadapter, int(ptf_t1_intf.strip("eth")), pkt, count=10)


def test_active_tor_downstream_active(
    apply_mock_dual_tor_tables,
    apply_mock_dual_tor_kernel_configs,
    apply_active_state_to_orchagent,
    conn_graph_facts, tbinfo,
    build_packet_to_server, rand_selected_interface, ptfadapter,
    rand_selected_dut, vmhost,
):

    def build_exp_pkt(packet):
        exp_pkt = mask.Mask(packet)
        exp_pkt.set_do_not_care_scapy(Ether, "dst")
        exp_pkt.set_do_not_care_scapy(Ether, "src")
        exp_pkt.set_do_not_care_scapy(IP, "tos")
        exp_pkt.set_do_not_care_scapy(IP, "ttl")
        exp_pkt.set_do_not_care_scapy(IP, "chksum")
        return exp_pkt

    tor = rand_selected_dut
    pkt = build_packet_to_server
    iface, server_details = rand_selected_interface
    server_ipv4 = server_details["server_ipv4"].split("/")[0]

    exp_pkt = build_exp_pkt(pkt)

    ptf_t1_intf = random.choice(get_t1_ptf_ports(tor, tbinfo))
    logging.info("send traffic to server %s from ptf t1 interface %s", server_ipv4, ptf_t1_intf)
    with ServerTrafficMonitor(tor, vmhost, iface, conn_graph_facts, exp_pkt, existing=True):
        testutils.send(ptfadapter, int(ptf_t1_intf.strip("eth")), pkt, count=10)
        time.sleep(1)

• result

dualtor/test_vmhost.py::test_standby_tor_remove_neighbor_downstream_standby PASSED                                                                                                             [ 50%]
dualtor/test_vmhost.py::test_active_tor_downstream_active PASSED                                                                                                                               [100%]

===================================================================================== 2 passed in 45.65 seconds ======================================================================================

Any platform specific information?

Supported testbed topology if it's a new test case?

Documentation

[lgtm-com]

This pull request introduces 1 alert when merging 2594da0 into 6429d31 - view on LGTM.com

new alerts:

• 1 for Unused import

[lolyu]

/AZP run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[lgtm-com]

This pull request introduces 1 alert when merging 1f4566a into 60d73a0 - view on LGTM.com

new alerts:

• 1 for Unused import

[wangxin]

LGTM. BTW, can you address the LGTM alert?