test/test_mdata.py

from framework import VppTestCase, VppTestRunner
import unittest
from config import config
from scapy.layers.l2 import Ether
from scapy.packet import Raw
from scapy.layers.inet import IP, UDP
from random import randint
from util import ppp


@unittest.skipIf("mdata" in config.excluded_plugins, "Exclude mdata plugin tests")
class TestMdataCli(VppTestCase):
    """mdata plugin test"""

    @classmethod
    def setUpClass(cls):
        super(TestMdataCli, cls).setUpClass()
        try:
            cls.create_pg_interfaces(range(2))
            for i in cls.pg_interfaces:
                i.config_ip4()
                i.resolve_arp()
                i.admin_up()
        except Exception:
            cls.tearDownClass()
            raise

    @classmethod
    def tearDownClass(cls):
        for i in cls.pg_interfaces:
            i.unconfig_ip4()
            i.admin_down()
        super(TestMdataCli, cls).tearDownClass()

    # https://fd.io/docs/vpp/master/developer/tests/overview.html#example-how-to-add-a-new-test
    def create_stream(self, src_if, dst_if, count):
        packets = []
        for i in range(count):
            info = self.create_packet_info(src_if, dst_if)
            payload = self.info_to_payload(info)

            p = (
                Ether(dst=src_if.local_mac, src=src_if.remote_mac)
                / IP(src=src_if.remote_ip4, dst=dst_if.remote_ip4)
                / UDP(sport=randint(49152, 65535), dport=5678)
                / Raw(payload)
            )

            info.data = p.copy()
            packets.append(p)

        return packets

    def verify_capture(self, src_if, dst_if, capture):
        packet_info = None
        for packet in capture:
            try:
                ip = packet[IP]
                udp = packet[UDP]
                # convert the payload to packet info object
                payload_info = self.payload_to_info(packet[Raw])
                # make sure the indexes match
                self.assert_equal(
                    payload_info.src, src_if.sw_if_index, "source sw_if_index"
                )
                self.assert_equal(
                    payload_info.dst, dst_if.sw_if_index, "destination sw_if_index"
                )
                packet_info = self.get_next_packet_info_for_interface2(
                    src_if.sw_if_index, dst_if.sw_if_index, packet_info
                )
                # make sure we didn't run out of saved packets
                self.assertIsNotNone(packet_info)
                self.assert_equal(
                    payload_info.index, packet_info.index, "packet info index"
                )
                saved_packet = packet_info.data  # fetch the saved packet
                # assert the values match
                self.assert_equal(ip.src, saved_packet[IP].src, "IP source address")
                # ... more assertions here
                self.assert_equal(udp.sport, saved_packet[UDP].sport, "UDP source port")
            except Exception:
                self.logger.error(ppp("Unexpected or invalid packet:", packet))
                raise
        remaining_packet = self.get_next_packet_info_for_interface2(
            src_if.sw_if_index, dst_if.sw_if_index, packet_info
        )
        self.assertIsNone(
            remaining_packet,
            "Interface %s: Packet expected from interface "
            "%s didn't arrive" % (dst_if.name, src_if.name),
        )

    def test_mdata_cli(self):
        """turn on mdata tracking, send packets, verify, check CLI output"""
        self.vapi.cli("buffer metadata tracking on")

        packets = self.create_stream(self.pg0, self.pg1, 5)
        self.pg0.add_stream(packets)
        self.pg0.enable_capture()
        self.pg1.enable_capture()
        self.pg_start()

        capture = self.pg1.get_capture()
        self.pg0.assert_nothing_captured()
        self.verify_capture(self.pg0, self.pg1, capture)

        result = self.vapi.cli("show buffer metadata")
        expected = [
            "ip4-input",
            "ip4-rewrite",
            "ip4-lookup",
            "ethernet-input",
            "pg1-tx",
            "pg1-output",
        ]
        for entry in expected:
            self.assertIn(entry, result)
        self.vapi.cli("buffer metadata tracking off")


if __name__ == "__main__":
    unittest.main(testRunner=VppTestRunner)