path: root/tools/pkt_gen/trex/trex.py

# Copyright 2017 Martin Goldammer, OPNFV, Red Hat Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
"""
Trex Traffic Generator Model
"""

# pylint: disable=undefined-variable
import logging
import subprocess
import sys
import time
import os
import re
from collections import OrderedDict
# pylint: disable=unused-import
import netaddr
import zmq
from conf import settings
from conf import merge_spec
from core.results.results_constants import ResultsConstants
from tools.pkt_gen.trafficgen.trafficgen import ITrafficGenerator
try:
    # pylint: disable=wrong-import-position, import-error
    sys.path.append(settings.getValue('PATHS')['trafficgen']['Trex']['src']['path'])
    from trex_stl_lib.api import *
    from trex_stl_lib import trex_stl_exceptions
except ImportError:
    # VSPERF performs detection of T-Rex api during testcase initialization. So if
    # T-Rex is requsted and API is not available it will fail before this code
    # is reached.
    # This code can be reached in case that --list-trafficgens is called, but T-Rex
    # api is not installed. In this case we can ignore an exception, becuase T-Rex
    # import won't be used.
    pass

_EMPTY_STATS = {
    'global': {'bw_per_core': 0.0,
               'cpu_util': 0.0,
               'queue_full': 0.0,
               'rx_bps': 0.0,
               'rx_cpu_util': 0.0,
               'rx_drop_bps': 0.0,
               'rx_pps': 0.0,
               'tx_bps': 0.0,
               'tx_pps': 0.0,},
    'latency': {},
    'total': {'ibytes': 0.0,
              'ierrors': 0.0,
              'ipackets': 0.0,
              'obytes': 0.0,
              'oerrors': 0.0,
              'opackets': 0.0,
              'rx_bps': 0.0,
              'rx_bps_L1': 0.0,
              'rx_pps': 0.0,
              'rx_util': 0.0,
              'tx_bps': 0.0,
              'tx_bps_L1': 0.0,
              'tx_pps': 0.0,
              'tx_util': 0.0,}}

# Default frame definition, which can be overridden by TRAFFIC['scapy'].
# The content of the frame and its network layers are driven by TRAFFIC
# dictionary, i.e. 'l2', 'l3, 'l4' and 'vlan' parts.
_SCAPY_FRAME = {
    '0' : 'Ether(src={Ether_src}, dst={Ether_dst})/'
          'Dot1Q(prio={Dot1Q_prio}, id={Dot1Q_id}, vlan={Dot1Q_vlan})/'
          'IP(proto={IP_proto}, src={IP_src}, dst={IP_dst})/'
          '{IP_PROTO}(sport={IP_PROTO_sport}, dport={IP_PROTO_dport})',
    '1' : 'Ether(src={Ether_dst}, dst={Ether_src})/'
          'Dot1Q(prio={Dot1Q_prio}, id={Dot1Q_id}, vlan={Dot1Q_vlan})/'
          'IP(proto={IP_proto}, src={IP_dst}, dst={IP_src})/'
          '{IP_PROTO}(sport={IP_PROTO_dport}, dport={IP_PROTO_sport})',
}


class Trex(ITrafficGenerator):
    """Trex Traffic generator wrapper."""
    _logger = logging.getLogger(__name__)

    def __init__(self):
        """Trex class constructor."""
        super().__init__()
        self._logger.info("In trex __init__ method")
        self._params = {}
        self._trex_host_ip_addr = (
            settings.getValue('TRAFFICGEN_TREX_HOST_IP_ADDR'))
        self._trex_base_dir = (
            settings.getValue('TRAFFICGEN_TREX_BASE_DIR'))
        self._trex_user = settings.getValue('TRAFFICGEN_TREX_USER')
        self._stlclient = None
        self._verification_params = None
        self._show_packet_data = False

    def show_packet_info(self, packet_a, packet_b):
        """
        Log packet layers to screen
        :param packet_a: Scapy.layers packet
        :param packet_b: Scapy.layers packet
        :return: None
        """
        # we only want to show packet data once per test
        if self._show_packet_data:
            self._show_packet_data = False
            self._logger.info(packet_a.show())
            self._logger.info(packet_b.show())

    def connect(self):
        '''Connect to Trex traffic generator

        Verify that Trex is on the system indicated by
        the configuration file
        '''
        self._stlclient = STLClient()
        self._logger.info("T-Rex:  In Trex connect method...")
        if self._trex_host_ip_addr:
            cmd_ping = "ping -c1 " + self._trex_host_ip_addr
        else:
            raise RuntimeError('T-Rex: Trex host not defined')

        ping = subprocess.Popen(cmd_ping, shell=True, stderr=subprocess.PIPE)
        output, error = ping.communicate()

        if ping.returncode:
            self._logger.error(error)
            self._logger.error(output)
            raise RuntimeError('T-Rex: Cannot ping Trex host at ' + \
                               self._trex_host_ip_addr)

        connect_trex = "ssh " + self._trex_user + \
                          "@" + self._trex_host_ip_addr

        cmd_find_trex = connect_trex + " ls " + \
                          self._trex_base_dir + "t-rex-64"


        find_trex = subprocess.Popen(cmd_find_trex,
                                     shell=True,
                                     stderr=subprocess.PIPE)
        output, error = find_trex.communicate()

        if find_trex.returncode:
            self._logger.error(error)
            self._logger.error(output)
            raise RuntimeError(
                'T-Rex: Cannot locate Trex program at %s within %s' \
                % (self._trex_host_ip_addr, self._trex_base_dir))

        try:
            self._stlclient = STLClient(username=self._trex_user, server=self._trex_host_ip_addr,
                                        verbose_level=0)
            self._stlclient.connect()
        except STLError:
            raise RuntimeError('T-Rex: Cannot connect to T-Rex server. Please check if it is '
                               'running and that firewall allows connection to TCP port 4501.')

        self._logger.info("T-Rex: Trex host successfully found...")

    def disconnect(self):
        """Disconnect from the traffic generator.

        As with :func:`connect`, this function is optional.

        Where implemented, this function should raise an exception on
        failure.

        :returns: None
        """
        self._logger.info("T-Rex: In trex disconnect method")
        self._stlclient.disconnect(stop_traffic=True, release_ports=True)

    def create_packets(self, traffic, ports_info):
        """Create base packet according to traffic specification.
           If traffic haven't specified srcmac and dstmac fields
           packet will be created with mac address of trex server.
        """
        if not traffic or traffic['l2']['framesize'] <= 0:
            return (None, None)

        if traffic['l2']['dstmac'] == '00:00:00:00:00:00' and \
           traffic['l2']['srcmac'] == '00:00:00:00:00:00':

            mac_add = [li['hw_mac'] for li in ports_info]
            src_mac = mac_add[0]
            dst_mac = mac_add[1]
        else:
            src_mac = traffic['l2']['srcmac']
            dst_mac = traffic['l2']['dstmac']

        if traffic['scapy']['enabled']:
            base_pkt_a = traffic['scapy']['0']
            base_pkt_b = traffic['scapy']['1']
        else:
            base_pkt_a = _SCAPY_FRAME['0']
            base_pkt_b = _SCAPY_FRAME['1']

        # check and remove network layers disabled by TRAFFIC dictionary
        # Note: In general, it is possible to remove layers from scapy object by
        # e.g. del base_pkt_a['IP']. However it doesn't work for all layers
        # (e.g. Dot1Q). Thus it is safer to modify string with scapy frame definition
        # directly, before it is converted to the real scapy object.
        if not traffic['vlan']['enabled']:
            self._logger.info('VLAN headers are disabled by TRAFFIC')
            base_pkt_a = re.sub(r'(^|\/)Dot1Q?\([^\)]*\)', '', base_pkt_a)
            base_pkt_b = re.sub(r'(^|\/)Dot1Q?\([^\)]*\)', '', base_pkt_b)
        if not traffic['l3']['enabled']:
            self._logger.info('IP headers are disabled by TRAFFIC')
            base_pkt_a = re.sub(r'(^|\/)IP(v6)?\([^\)]*\)', '', base_pkt_a)
            base_pkt_b = re.sub(r'(^|\/)IP(v6)?\([^\)]*\)', '', base_pkt_b)
        if not traffic['l4']['enabled']:
            self._logger.info('%s headers are disabled by TRAFFIC',
                              traffic['l3']['proto'].upper())
            base_pkt_a = re.sub(r'(^|\/)(UDP|TCP|SCTP|{{IP_PROTO}}|{})\([^\)]*\)'.format(
                traffic['l3']['proto'].upper()), '', base_pkt_a)
            base_pkt_b = re.sub(r'(^|\/)(UDP|TCP|SCTP|{{IP_PROTO}}|{})\([^\)]*\)'.format(
                traffic['l3']['proto'].upper()), '', base_pkt_b)

        # pylint: disable=eval-used
        base_pkt_a = eval(base_pkt_a.format(
            Ether_src=repr(src_mac),
            Ether_dst=repr(dst_mac),
            Dot1Q_prio=traffic['vlan']['priority'],
            Dot1Q_id=traffic['vlan']['cfi'],
            Dot1Q_vlan=traffic['vlan']['id'],
            IP_proto=repr(traffic['l3']['proto']),
            IP_PROTO=traffic['l3']['proto'].upper(),
            IP_src=repr(traffic['l3']['srcip']),
            IP_dst=repr(traffic['l3']['dstip']),
            IP_PROTO_sport=traffic['l4']['srcport'],
            IP_PROTO_dport=traffic['l4']['dstport']))
        base_pkt_b = eval(base_pkt_b.format(
            Ether_src=repr(src_mac),
            Ether_dst=repr(dst_mac),
            Dot1Q_prio=traffic['vlan']['priority'],
            Dot1Q_id=traffic['vlan']['cfi'],
            Dot1Q_vlan=traffic['vlan']['id'],
            IP_proto=repr(traffic['l3']['proto']),
            IP_PROTO=traffic['l3']['proto'].upper(),
            IP_src=repr(traffic['l3']['srcip']),
            IP_dst=repr(traffic['l3']['dstip']),
            IP_PROTO_sport=traffic['l4']['srcport'],
            IP_PROTO_dport=traffic['l4']['dstport']))

        return (base_pkt_a, base_pkt_b)

    @staticmethod
    def create_streams(base_pkt_a, base_pkt_b, traffic):
        """Add the base packet to the streams. Erase FCS and add payload
           according to traffic specification
        """
        stream_1_lat = None
        stream_2_lat = None
        frame_size = int(traffic['l2']['framesize'])
        fsize_no_fcs = frame_size - 4
        payload_a = max(0, fsize_no_fcs - len(base_pkt_a)) * 'x'
        payload_b = max(0, fsize_no_fcs - len(base_pkt_b)) * 'x'

        # Multistream configuration, increments source values only
        ms_mod = list() # mod list for incrementing values to be populated based on layer
        if traffic['multistream'] > 1:
            if traffic['stream_type'].upper() == 'L2':
                for _ in [base_pkt_a, base_pkt_b]:
                    ms_mod += [STLVmFlowVar(name="mac_start", min_value=0,
                                            max_value=traffic['multistream'] - 1, size=4, op="inc"),
                               STLVmWrFlowVar(fv_name="mac_start", pkt_offset=7)]
            elif traffic['stream_type'].upper() == 'L3':
                ip_src = {"start": int(netaddr.IPAddress(traffic['l3']['srcip'])),
                          "end": int(netaddr.IPAddress(traffic['l3']['srcip'])) + traffic['multistream'] - 1}
                ip_dst = {"start": int(netaddr.IPAddress(traffic['l3']['dstip'])),
                          "end": int(netaddr.IPAddress(traffic['l3']['dstip'])) + traffic['multistream'] - 1}
                for ip_address in [ip_src, ip_dst]:
                    ms_mod += [STLVmFlowVar(name="ip_src", min_value=ip_address['start'],
                                            max_value=ip_address['end'], size=4, op="inc"),
                               STLVmWrFlowVar(fv_name="ip_src", pkt_offset="IP.src")]
            elif traffic['stream_type'].upper() == 'L4':
                for udpport in [traffic['l4']['srcport'], traffic['l4']['dstport']]:
                    if udpport + (traffic['multistream'] - 1) > 65535:
                        start_port = udpport
                        # find the max/min port number based on the loop around of 65535 to 0 if needed
                        minimum_value = 65535 - (traffic['multistream'] -1)
                        maximum_value = 65535
                    else:
                        start_port, minimum_value = udpport, udpport
                        maximum_value = start_port + (traffic['multistream'] - 1)
                    ms_mod += [STLVmFlowVar(name="port_src", init_value=start_port,
                                            min_value=minimum_value, max_value=maximum_value,
                                            size=2, op="inc"),
                               STLVmWrFlowVar(fv_name="port_src", pkt_offset="UDP.sport"),]

        if ms_mod: # multistream detected
            pkt_a = STLPktBuilder(pkt=base_pkt_a/payload_a, vm=[ms_mod[0], ms_mod[1]])
            pkt_b = STLPktBuilder(pkt=base_pkt_b/payload_b, vm=[ms_mod[2], ms_mod[3]])
        else:
            pkt_a = STLPktBuilder(pkt=base_pkt_a / payload_a)
            pkt_b = STLPktBuilder(pkt=base_pkt_b / payload_b)

        lat_pps = settings.getValue('TRAFFICGEN_TREX_LATENCY_PPS')
        if traffic['traffic_type'] == 'burst':
            if lat_pps > 0:
                # latency statistics are requested; in case of frame burst we can enable
                # statistics for all frames
                stream_1 = STLStream(packet=pkt_a,
                                     flow_stats=STLFlowLatencyStats(pg_id=0),
                                     name='stream_1',
                                     mode=STLTXSingleBurst(percentage=traffic['frame_rate'],
                                                           total_pkts=traffic['burst_size']))
                stream_2 = STLStream(packet=pkt_b,
                                     flow_stats=STLFlowLatencyStats(pg_id=1),
                                     name='stream_2',
                                     mode=STLTXSingleBurst(percentage=traffic['frame_rate'],
                                                           total_pkts=traffic['burst_size']))
            else:
                stream_1 = STLStream(packet=pkt_a,
                                     name='stream_1',
                                     mode=STLTXSingleBurst(percentage=traffic['frame_rate'],
                                                           total_pkts=traffic['burst_size']))
                stream_2 = STLStream(packet=pkt_b,
                                     name='stream_2',
                                     mode=STLTXSingleBurst(percentage=traffic['frame_rate'],
                                                           total_pkts=traffic['burst_size']))
        else:
            stream_1 = STLStream(packet=pkt_a,
                                 name='stream_1',
                                 mode=STLTXCont(percentage=traffic['frame_rate']))
            stream_2 = STLStream(packet=pkt_b,
                                 name='stream_2',
                                 mode=STLTXCont(percentage=traffic['frame_rate']))
            # workaround for latency statistics, which can't be enabled for streams
            # with high framerate due to the huge performance impact
            if lat_pps > 0:
                stream_1_lat = STLStream(packet=pkt_a,
                                         flow_stats=STLFlowLatencyStats(pg_id=0),
                                         name='stream_1_lat',
                                         mode=STLTXCont(pps=lat_pps))
                stream_2_lat = STLStream(packet=pkt_b,
                                         flow_stats=STLFlowLatencyStats(pg_id=1),
                                         name='stream_2_lat',
                                         mode=STLTXCont(pps=lat_pps))

        return (stream_1, stream_2, stream_1_lat, stream_2_lat)


    # pylint: disable=too-many-locals, too-many-statements
    def generate_traffic(self, traffic, duration, disable_capture=False):
        """The method that generate a stream
        """
        my_ports = [0, 1]

        # initialize ports
        self._stlclient.reset(my_ports)
        self._stlclient.remove_all_captures()
        self._stlclient.set_service_mode(ports=my_ports, enabled=False)

        ports_info = self._stlclient.get_port_info(my_ports)

        # get max support speed
        max_speed = 0
        if settings.getValue('TRAFFICGEN_TREX_FORCE_PORT_SPEED'):
            max_speed = settings.getValue('TRAFFICGEN_TREX_PORT_SPEED')
        elif ports_info[0]['supp_speeds']:
            max_speed_1 = max(ports_info[0]['supp_speeds'])
            max_speed_2 = max(ports_info[1]['supp_speeds'])
        else:
            # if max supported speed not in port info or set manually, just assume 10G
            max_speed = 10000
        if not max_speed:
            # since we can only control both ports at once take the lower of the two
            max_speed = min(max_speed_1, max_speed_2)
        gbps_speed = (max_speed / 1000) * (float(traffic['frame_rate']) / 100.0)
        self._logger.debug('Starting traffic at %s Gbps speed', gbps_speed)

        # for SR-IOV
        if settings.getValue('TRAFFICGEN_TREX_PROMISCUOUS'):
            self._stlclient.set_port_attr(my_ports, promiscuous=True)

        packet_1, packet_2 = self.create_packets(traffic, ports_info)
        self.show_packet_info(packet_1, packet_2)
        stream_1, stream_2, stream_1_lat, stream_2_lat = Trex.create_streams(packet_1, packet_2, traffic)
        self._stlclient.add_streams(stream_1, ports=[0])
        self._stlclient.add_streams(stream_2, ports=[1])

        if stream_1_lat is not None:
            self._stlclient.add_streams(stream_1_lat, ports=[0])
            self._stlclient.add_streams(stream_2_lat, ports=[1])

        # enable traffic capture if requested
        pcap_id = {}
        if traffic['capture']['enabled'] and not disable_capture:
            for ports in ['tx_ports', 'rx_ports']:
                if traffic['capture'][ports]:
                    pcap_dir = ports[:2]
                    self._logger.info("T-Rex starting %s traffic capture", pcap_dir.upper())
                    capture = {ports : traffic['capture'][ports],
                               'limit' : traffic['capture']['count'],
                               'bpf_filter' : traffic['capture']['filter']}
                    self._stlclient.set_service_mode(ports=traffic['capture'][ports], enabled=True)
                    pcap_id[pcap_dir] = self._stlclient.start_capture(**capture)

        self._stlclient.clear_stats()
        # if the user did not start up T-Rex server with more than default cores, use default mask.
        # Otherwise use mask to take advantage of multiple cores.
        try:
            self._stlclient.start(ports=my_ports, force=True, duration=duration, mult="{}gbps".format(gbps_speed),
                                  core_mask=self._stlclient.CORE_MASK_PIN)
        except STLError:
            self._stlclient.start(ports=my_ports, force=True, duration=duration, mult="{}gbps".format(gbps_speed))

        if settings.getValue('TRAFFICGEN_TREX_LIVE_RESULTS'):
            filec = os.path.join(settings.getValue('RESULTS_PATH'),
                                 settings.getValue('TRAFFICGEN_TREX_LC_FILE'))
            filee = os.path.join(settings.getValue('RESULTS_PATH'),
                                 settings.getValue('TRAFFICGEN_TREX_LE_FILE'))
            pgids = self._stlclient.get_active_pgids()
            rx_port_0 = 1
            tx_port_0 = 0
            rx_port_1 = 0
            tx_port_1 = 1
            with open(filec, 'a') as fcp, open(filee, 'a') as fep:
                fcp.write("ts,rx_port,tx_port,rx_pkts,tx_pkts,rx_pps,tx_pps,"+
                          "rx_bps_num,rx_bps_den,tx_bps_num,tx_bps_den\n")
                fep.write('ts,dropped,ooo,dup,seq_too_high,seq_too_low\n')
                while True:
                    tr_status = self._stlclient.is_traffic_active(ports=my_ports)
                    if not tr_status:
                        break
                    time.sleep(1)
                    stats = self._stlclient.get_pgid_stats(pgids['flow_stats'])
                    lat_stats = stats['latency'].get(0)
                    flow_stats_0 = stats['flow_stats'].get(0)
                    flow_stats_1 = stats['flow_stats'].get(1)
                    if flow_stats_0:
                        rx_pkts = flow_stats_0['rx_pkts'][rx_port_0]
                        tx_pkts = flow_stats_0['tx_pkts'][tx_port_0]
                        rx_pps = flow_stats_0['rx_pps'][rx_port_0]
                        tx_pps = flow_stats_0['tx_pps'][tx_port_0]
                        rx_bps = flow_stats_0['rx_bps'][rx_port_0]
                        tx_bps = flow_stats_0['tx_bps'][tx_port_0]
                        rx_bps_l1 = flow_stats_0['rx_bps_l1'][rx_port_0]
                        tx_bps_l1 = flow_stats_0['tx_bps_l1'][tx_port_0]
                        # https://github.com/cisco-system-traffic-generator/\
                        # trex-core/blob/master/scripts/automation/\
                        # trex_control_plane/interactive/trex/examples/\
                        # stl/stl_flow_latency_stats.py
                        fcp.write("{10},{8},{9},{0},{1},{2},{3},{4},{5},{6},{7}\n"
                                  .format(rx_pkts, tx_pkts, rx_pps, tx_pps,
                                          rx_bps, rx_bps_l1, tx_bps, tx_bps_l1,
                                          rx_port_0, tx_port_0, time.time()))
                    if flow_stats_1:
                        rx_pkts = flow_stats_1['rx_pkts'][rx_port_1]
                        tx_pkts = flow_stats_1['tx_pkts'][tx_port_1]
                        rx_pps = flow_stats_1['rx_pps'][rx_port_1]
                        tx_pps = flow_stats_1['tx_pps'][tx_port_1]
                        rx_bps = flow_stats_1['rx_bps'][rx_port_1]
                        tx_bps = flow_stats_1['tx_bps'][tx_port_1]
                        rx_bps_l1 = flow_stats_1['rx_bps_l1'][rx_port_1]
                        tx_bps_l1 = flow_stats_1['tx_bps_l1'][tx_port_1]
                        fcp.write("{10},{8},{9},{0},{1},{2},{3},{4},{5},{6},{7}\n"
                                  .format(rx_pkts, tx_pkts, rx_pps, tx_pps,
                                          rx_bps, rx_bps_l1, tx_bps, tx_bps_l1,
                                          rx_port_1, tx_port_1, time.time()))
                    if lat_stats:
                        drops = lat_stats['err_cntrs']['dropped']
                        ooo = lat_stats['err_cntrs']['out_of_order']
                        dup = lat_stats['err_cntrs']['dup']
                        sth = lat_stats['err_cntrs']['seq_too_high']
                        stl = lat_stats['err_cntrs']['seq_too_low']
                        fep.write('{5},{0},{1},{2},{3},{4}\n'
                                  .format(drops, ooo, dup, sth, stl, time.time()))
        else:
            self._stlclient.wait_on_traffic(ports=my_ports)
        stats = self._stlclient.get_stats(sync_now=True)

        # export captured data into pcap file if possible
        if pcap_id:
            for pcap_dir in pcap_id:
                pcap_file = 'capture_{}.pcap'.format(pcap_dir)
                self._stlclient.stop_capture(pcap_id[pcap_dir]['id'],
                                             os.path.join(settings.getValue('RESULTS_PATH'), pcap_file))
                stats['capture_{}'.format(pcap_dir)] = pcap_file
                self._logger.info("T-Rex writing %s traffic capture into %s", pcap_dir.upper(), pcap_file)
            # disable service mode for all ports used by Trex
            self._stlclient.set_service_mode(ports=my_ports, enabled=False)

        return stats

    @staticmethod
    def calculate_results(stats):
        """Calculate results from Trex statistic
        """
        result = OrderedDict()
        result[ResultsConstants.TX_FRAMES] = (
            stats["total"]["opackets"])
        result[ResultsConstants.RX_FRAMES] = (
            stats["total"]["ipackets"])
        result[ResultsConstants.TX_RATE_FPS] = (
            '{:.3f}'.format(
                float(stats["total"]["tx_pps"])))

        result[ResultsConstants.THROUGHPUT_RX_FPS] = (
            '{:.3f}'.format(
                float(stats["total"]["rx_pps"])))

        result[ResultsConstants.TX_RATE_MBPS] = (
            '{:.3f}'.format(
                float(stats["total"]["tx_bps"] / 1000000)))
        result[ResultsConstants.THROUGHPUT_RX_MBPS] = (
            '{:.3f}'.format(
                float(stats["total"]["rx_bps"] / 1000000)))

        result[ResultsConstants.TX_RATE_PERCENT] = 'Unknown'

        result[ResultsConstants.THROUGHPUT_RX_PERCENT] = 'Unknown'
        if stats["total"]["opackets"]:
            result[ResultsConstants.FRAME_LOSS_PERCENT] = (
                '{:.3f}'.format(
                    float((stats["total"]["opackets"] - stats["total"]["ipackets"]) * 100 /
                          stats["total"]["opackets"])))
        else:
            result[ResultsConstants.FRAME_LOSS_PERCENT] = 100

        if settings.getValue('TRAFFICGEN_TREX_LATENCY_PPS') > 0 and stats['latency']:
            try:
                result[ResultsConstants.MIN_LATENCY_NS] = (
                    '{:.3f}'.format(
                        (float(min(stats["latency"][0]["latency"]["total_min"],
                                   stats["latency"][1]["latency"]["total_min"])))))
            except TypeError:
                result[ResultsConstants.MIN_LATENCY_NS] = 'Unknown'

            try:
                result[ResultsConstants.MAX_LATENCY_NS] = (
                    '{:.3f}'.format(
                        (float(max(stats["latency"][0]["latency"]["total_max"],
                                   stats["latency"][1]["latency"]["total_max"])))))
            except TypeError:
                result[ResultsConstants.MAX_LATENCY_NS] = 'Unknown'

            try:
                result[ResultsConstants.AVG_LATENCY_NS] = (
                    '{:.3f}'.format(
                        float((stats["latency"][0]["latency"]["average"]+
                               stats["latency"][1]["latency"]["average"])/2)))
            except TypeError:
                result[ResultsConstants.AVG_LATENCY_NS] = 'Unknown'

        else:
            result[ResultsConstants.MIN_LATENCY_NS] = 'Unknown'
            result[ResultsConstants.MAX_LATENCY_NS] = 'Unknown'
            result[ResultsConstants.AVG_LATENCY_NS] = 'Unknown'

        if 'capture_tx' in stats:
            result[ResultsConstants.CAPTURE_TX] = stats['capture_tx']
        if 'capture_rx' in stats:
            result[ResultsConstants.CAPTURE_RX] = stats['capture_rx']
        return result

    def learning_packets(self, traffic):
        """
        Send learning packets before testing
        :param traffic: traffic structure as per send_cont_traffic guidelines
        :return: None
        """
        self._logger.info("T-Rex sending learning packets")
        learning_thresh_traffic = copy.deepcopy(traffic)
        learning_thresh_traffic["frame_rate"] = 1
        self.generate_traffic(learning_thresh_traffic,
                              settings.getValue("TRAFFICGEN_TREX_LEARNING_DURATION"),
                              disable_capture=True)
        self._logger.info("T-Rex finished learning packets")
        time.sleep(3)  # allow packets to complete before starting test traffic

    def run_trials(self, traffic, boundaries, duration, lossrate):
        """
        Run rfc2544 trial loop
        :param traffic: traffic profile dictionary
        :param boundaries: A dictionary of three keys left, right, center to dictate
                          the highest, lowest, and starting point of the binary search.
                          Values are percentages of line rates for each key.
        :param duration: length in seconds for trials
        :param lossrate: loweset loss rate percentage calculated from
                         comparision between received and sent packets
        :return: passing stats as dictionary
        """
        threshold = settings.getValue('TRAFFICGEN_TREX_RFC2544_TPUT_THRESHOLD')
        stats_ok = _EMPTY_STATS
        new_params = copy.deepcopy(traffic)
        iteration = 1
        left = boundaries['left']
        right = boundaries['right']
        center = boundaries['center']
        self._logger.info('Starting RFC2544 trials')
        while (right - left) > threshold:
            stats = self.generate_traffic(new_params, duration)
            test_lossrate = ((stats["total"]["opackets"] - stats[
                "total"]["ipackets"]) * 100) / stats["total"]["opackets"]
            if stats["total"]["ipackets"] == 0:
                self._logger.error('No packets recieved. Test failed')
                return _EMPTY_STATS
            if settings.getValue('TRAFFICGEN_TREX_VERIFICATION_MODE'):
                if test_lossrate <= lossrate:
                    # save the last passing trial for verification
                    self._verification_params = copy.deepcopy(new_params)
            packets_lost = stats['total']['opackets'] - stats['total']['ipackets']
            self._logger.debug("Iteration: %s, frame rate: %s, throughput_rx_fps: %s," +
                               " frames lost %s, frame_loss_percent: %s", iteration,
                               "{:.3f}".format(new_params['frame_rate']), stats['total']['rx_pps'],
                               packets_lost, "{:.3f}".format(test_lossrate))
            if test_lossrate == 0.0 and new_params['frame_rate'] == traffic['frame_rate']:
                return copy.deepcopy(stats)
            elif test_lossrate > lossrate:
                right = center
                center = (left + right) / 2
                new_params = copy.deepcopy(traffic)
                new_params['frame_rate'] = center
            else:
                stats_ok = copy.deepcopy(stats)
                left = center
                center = (left + right) / 2
                new_params = copy.deepcopy(traffic)
                new_params['frame_rate'] = center
            iteration += 1
        return stats_ok

    def send_cont_traffic(self, traffic=None, duration=30):
        """See ITrafficGenerator for description
        """
        self._logger.info("In Trex send_cont_traffic method")
        self._params.clear()

        self._show_packet_data = True

        self._params['traffic'] = self.traffic_defaults.copy()
        if traffic:
            self._params['traffic'] = merge_spec(
                self._params['traffic'], traffic)

        if settings.getValue('TRAFFICGEN_TREX_LEARNING_MODE'):
            self.learning_packets(traffic)
        self._logger.info("T-Rex sending traffic")
        stats = self.generate_traffic(traffic, duration)

        return self.calculate_results(stats)

    def start_cont_traffic(self, traffic=None, duration=30):
        raise NotImplementedError(
            'Trex start cont traffic not implemented')

    def stop_cont_traffic(self):
        """See ITrafficGenerator for description
        """
        raise NotImplementedError(
            'Trex stop_cont_traffic method not implemented')

    def send_rfc2544_throughput(self, traffic=None, tests=1, duration=60,
                                lossrate=0.0):
        """See ITrafficGenerator for description
        """
        self._logger.info("In Trex send_rfc2544_throughput method")
        self._params.clear()
        self._show_packet_data = True
        self._params['traffic'] = self.traffic_defaults.copy()
        if traffic:
            self._params['traffic'] = merge_spec(
                self._params['traffic'], traffic)
        if settings.getValue('TRAFFICGEN_TREX_LEARNING_MODE'):
            self.learning_packets(traffic)
        self._verification_params = copy.deepcopy(traffic)

        binary_bounds = {'right' : traffic['frame_rate'],
                         'left'  : 0,
                         'center': traffic['frame_rate'],}

        # Loops until the preconfigured differencde between frame rate
        # of successful and unsuccessful iterations is reached
        stats_ok = self.run_trials(boundaries=binary_bounds, duration=duration,
                                   lossrate=lossrate, traffic=traffic)
        if settings.getValue('TRAFFICGEN_TREX_VERIFICATION_MODE'):
            verification_iterations = 1
            while verification_iterations <= settings.getValue('TRAFFICGEN_TREX_MAXIMUM_VERIFICATION_TRIALS'):
                self._logger.info('Starting Trex Verification trial for %s seconds at frame rate %s',
                                  settings.getValue('TRAFFICGEN_TREX_VERIFICATION_DURATION'),
                                  self._verification_params['frame_rate'])
                stats = self.generate_traffic(self._verification_params,
                                              settings.getValue('TRAFFICGEN_TREX_VERIFICATION_DURATION'))
                verification_lossrate = ((stats["total"]["opackets"] - stats[
                    "total"]["ipackets"]) * 100) / stats["total"]["opackets"]
                if verification_lossrate <= lossrate:
                    self._logger.info('Trex Verification passed, %s packets were lost',
                                      stats["total"]["opackets"] - stats["total"]["ipackets"])
                    stats_ok = copy.deepcopy(stats)
                    break
                else:
                    self._logger.info('Trex Verification failed, %s packets were lost',
                                      stats["total"]["opackets"] - stats["total"]["ipackets"])
                    new_right = self._verification_params['frame_rate'] - settings.getValue(
                        'TRAFFICGEN_TREX_RFC2544_TPUT_THRESHOLD')
                    self._verification_params['frame_rate'] = new_right
                    binary_bounds = {'right': new_right,
                                     'left': 0,
                                     'center': new_right,}
                    stats_ok = self.run_trials(boundaries=binary_bounds, duration=duration,
                                               lossrate=lossrate, traffic=self._verification_params)
                verification_iterations += 1
            else:
                self._logger.error('Could not pass Trex Verification. Test failed')
        return self.calculate_results(stats_ok)

    def start_rfc2544_throughput(self, traffic=None, tests=1, duration=60,
                                 lossrate=0.0):
        raise NotImplementedError(
            'Trex start rfc2544 throughput not implemented')

    def wait_rfc2544_throughput(self):
        raise NotImplementedError(
            'Trex wait rfc2544 throughput not implemented')

    def send_burst_traffic(self, traffic=None, duration=20):
        """See ITrafficGenerator for description
        """
        self._logger.info("In Trex send_burst_traffic method")
        self._params.clear()

        self._params['traffic'] = self.traffic_defaults.copy()
        if traffic:
            self._params['traffic'] = merge_spec(
                self._params['traffic'], traffic)

        if settings.getValue('TRAFFICGEN_TREX_LEARNING_MODE'):
            self.learning_packets(traffic)
        self._logger.info("T-Rex sending traffic")
        stats = self.generate_traffic(traffic, duration)

        time.sleep(3)  # allow packets to complete before reading stats

        return self.calculate_results(stats)

    def send_rfc2544_back2back(self, traffic=None, tests=1, duration=30,
                               lossrate=0.0):
        raise NotImplementedError(
            'Trex send rfc2544 back2back not implemented')

    def start_rfc2544_back2back(self, traffic=None, tests=1, duration=30,
                                lossrate=0.0):
        raise NotImplementedError(
            'Trex start rfc2544 back2back not implemented')

    def wait_rfc2544_back2back(self):
        raise NotImplementedError(
            'Trex wait rfc2544 back2back not implemented')

if __name__ == "__main__":
    pass