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path: root/nfvbench/traffic_client.py
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# Copyright 2016 Cisco Systems, Inc.  All rights reserved.
#
#    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.

from datetime import datetime
import re
import socket
import struct
import time

from attrdict import AttrDict
import bitmath
from netaddr import IPNetwork
# pylint: disable=import-error
from trex_stl_lib.api import STLError
# pylint: enable=import-error

from log import LOG
from network import Interface
from specs import ChainType
from stats_collector import IntervalCollector
from stats_collector import IterationCollector
import traffic_gen.traffic_utils as utils
from utils import cast_integer


class TrafficClientException(Exception):
    pass


class TrafficRunner(object):
    def __init__(self, client, duration_sec, interval_sec=0):
        self.client = client
        self.start_time = None
        self.duration_sec = duration_sec
        self.interval_sec = interval_sec

    def run(self):
        LOG.info('Running traffic generator')
        self.client.gen.clear_stats()
        self.client.gen.start_traffic()
        self.start_time = time.time()
        return self.poll_stats()

    def stop(self):
        if self.is_running():
            self.start_time = None
            self.client.gen.stop_traffic()

    def is_running(self):
        return self.start_time is not None

    def time_elapsed(self):
        if self.is_running():
            return time.time() - self.start_time
        return self.duration_sec

    def poll_stats(self):
        if not self.is_running():
            return None
        if self.client.skip_sleep:
            self.stop()
            return self.client.get_stats()
        time_elapsed = self.time_elapsed()
        if time_elapsed > self.duration_sec:
            self.stop()
            return None
        time_left = self.duration_sec - time_elapsed
        if self.interval_sec > 0.0:
            if time_left <= self.interval_sec:
                time.sleep(time_left)
                self.stop()
            else:
                time.sleep(self.interval_sec)
        else:
            time.sleep(self.duration_sec)
            self.stop()
        return self.client.get_stats()


class IpBlock(object):
    def __init__(self, base_ip, step_ip, count_ip):
        self.base_ip_int = Device.ip_to_int(base_ip)
        self.step = Device.ip_to_int(step_ip)
        self.max_available = count_ip
        self.next_free = 0

    def get_ip(self, index=0):
        '''Return the IP address at given index
        '''
        if index < 0 or index >= self.max_available:
            raise IndexError('Index out of bounds')
        return Device.int_to_ip(self.base_ip_int + index * self.step)

    def reserve_ip_range(self, count):
        '''Reserve a range of count consecutive IP addresses spaced by step
        '''
        if self.next_free + count > self.max_available:
            raise IndexError('No more IP addresses next free=%d max_available=%d requested=%d' %
                             (self.next_free,
                              self.max_available,
                              count))
        first_ip = self.get_ip(self.next_free)
        last_ip = self.get_ip(self.next_free + count - 1)
        self.next_free += count
        return (first_ip, last_ip)

    def reset_reservation(self):
        self.next_free = 0


class Device(object):
    def __init__(self, port, pci, switch_port=None, vtep_vlan=None, ip=None, tg_gateway_ip=None,
                 gateway_ip=None, ip_addrs_step=None, tg_gateway_ip_addrs_step=None,
                 gateway_ip_addrs_step=None, udp_src_port=None, udp_dst_port=None,
                 dst_mac=None, chain_count=1, flow_count=1, vlan_tagging=False):
        self.chain_count = chain_count
        self.flow_count = flow_count
        self.dst = None
        self.port = port
        self.switch_port = switch_port
        self.vtep_vlan = vtep_vlan
        self.vlan_tag = None
        self.vlan_tagging = vlan_tagging
        self.pci = pci
        self.mac = None
        self.dst_mac = dst_mac
        self.vm_mac_list = None
        subnet = IPNetwork(ip)
        self.ip = subnet.ip.format()
        self.ip_prefixlen = subnet.prefixlen
        self.ip_addrs_step = ip_addrs_step
        self.tg_gateway_ip_addrs_step = tg_gateway_ip_addrs_step
        self.gateway_ip_addrs_step = gateway_ip_addrs_step
        self.gateway_ip = gateway_ip
        self.tg_gateway_ip = tg_gateway_ip
        self.ip_block = IpBlock(self.ip, ip_addrs_step, flow_count)
        self.gw_ip_block = IpBlock(gateway_ip,
                                   gateway_ip_addrs_step,
                                   chain_count)
        self.tg_gw_ip_block = IpBlock(tg_gateway_ip,
                                      tg_gateway_ip_addrs_step,
                                      chain_count)
        self.udp_src_port = udp_src_port
        self.udp_dst_port = udp_dst_port

    def set_mac(self, mac):
        if mac is None:
            raise TrafficClientException('Trying to set traffic generator MAC address as None')
        self.mac = mac

    def set_destination(self, dst):
        self.dst = dst

    def set_vm_mac_list(self, vm_mac_list):
        self.vm_mac_list = map(str, vm_mac_list)

    def set_vlan_tag(self, vlan_tag):
        if self.vlan_tagging and vlan_tag is None:
            raise TrafficClientException('Trying to set VLAN tag as None')
        self.vlan_tag = vlan_tag

    def get_gw_ip(self, chain_index):
        '''Retrieve the IP address assigned for the gateway of a given chain
        '''
        return self.gw_ip_block.get_ip(chain_index)

    def get_stream_configs(self, service_chain):
        configs = []
        # exact flow count for each chain is calculated as follows:
        # - all chains except the first will have the same flow count
        #   calculated as (total_flows + chain_count - 1) / chain_count
        # - the first chain will have the remainder
        # example 11 flows and 3 chains => 3, 4, 4
        flows_per_chain = (self.flow_count + self.chain_count - 1) / self.chain_count
        cur_chain_flow_count = self.flow_count - flows_per_chain * (self.chain_count - 1)

        self.ip_block.reset_reservation()
        self.dst.ip_block.reset_reservation()

        for chain_idx in xrange(self.chain_count):
            src_ip_first, src_ip_last = self.ip_block.reserve_ip_range(cur_chain_flow_count)
            dst_ip_first, dst_ip_last = self.dst.ip_block.reserve_ip_range(cur_chain_flow_count)

            dst_mac = self.dst_mac[chain_idx] if self.dst_mac is not None else self.dst.mac
            if not re.match("[0-9a-f]{2}([-:])[0-9a-f]{2}(\\1[0-9a-f]{2}){4}$", dst_mac.lower()):
                raise TrafficClientException("Invalid MAC address '{mac}' specified in "
                                             "mac_addrs_left/right".format(mac=dst_mac))

            configs.append({
                'count': cur_chain_flow_count,
                'mac_src': self.mac,
                'mac_dst': dst_mac if service_chain == ChainType.EXT else self.vm_mac_list[
                    chain_idx],
                'ip_src_addr': src_ip_first,
                'ip_src_addr_max': src_ip_last,
                'ip_src_count': cur_chain_flow_count,
                'ip_dst_addr': dst_ip_first,
                'ip_dst_addr_max': dst_ip_last,
                'ip_dst_count': cur_chain_flow_count,
                'ip_addrs_step': self.ip_addrs_step,
                'udp_src_port': self.udp_src_port,
                'udp_dst_port': self.udp_dst_port,
                'mac_discovery_gw': self.get_gw_ip(chain_idx),
                'ip_src_tg_gw': self.tg_gw_ip_block.get_ip(chain_idx),
                'ip_dst_tg_gw': self.dst.tg_gw_ip_block.get_ip(chain_idx),
                'vlan_tag': self.vlan_tag if self.vlan_tagging else None
            })
            # after first chain, fall back to the flow count for all other chains
            cur_chain_flow_count = flows_per_chain

        return configs

    def ip_range_overlaps(self):
        '''Check if this device ip range is overlapping with the dst device ip range
        '''
        src_base_ip = Device.ip_to_int(self.ip)
        dst_base_ip = Device.ip_to_int(self.dst.ip)
        src_last_ip = src_base_ip + self.flow_count - 1
        dst_last_ip = dst_base_ip + self.flow_count - 1
        return dst_last_ip >= src_base_ip and src_last_ip >= dst_base_ip

    @staticmethod
    def mac_to_int(mac):
        return int(mac.translate(None, ":.- "), 16)

    @staticmethod
    def int_to_mac(i):
        mac = format(i, 'x').zfill(12)
        blocks = [mac[x:x + 2] for x in xrange(0, len(mac), 2)]
        return ':'.join(blocks)

    @staticmethod
    def ip_to_int(addr):
        return struct.unpack("!I", socket.inet_aton(addr))[0]

    @staticmethod
    def int_to_ip(nvalue):
        return socket.inet_ntoa(struct.pack("!I", nvalue))


class RunningTrafficProfile(object):
    """Represents traffic configuration for currently running traffic profile."""

    DEFAULT_IP_STEP = '0.0.0.1'
    DEFAULT_SRC_DST_IP_STEP = '0.0.0.1'

    def __init__(self, config, generator_profile):
        generator_config = self.__match_generator_profile(config.traffic_generator,
                                                          generator_profile)
        self.generator_config = generator_config
        self.service_chain = config.service_chain
        self.service_chain_count = config.service_chain_count
        self.flow_count = config.flow_count
        self.host_name = generator_config.host_name
        self.name = generator_config.name
        self.tool = generator_config.tool
        self.cores = generator_config.get('cores', 1)
        self.ip_addrs_step = generator_config.ip_addrs_step or self.DEFAULT_SRC_DST_IP_STEP
        self.tg_gateway_ip_addrs_step = \
            generator_config.tg_gateway_ip_addrs_step or self.DEFAULT_IP_STEP
        self.gateway_ip_addrs_step = generator_config.gateway_ip_addrs_step or self.DEFAULT_IP_STEP
        self.gateway_ips = generator_config.gateway_ip_addrs
        self.ip = generator_config.ip
        self.intf_speed = bitmath.parse_string(generator_config.intf_speed.replace('ps', '')).bits
        self.vlan_tagging = config.vlan_tagging
        self.no_arp = config.no_arp
        self.src_device = None
        self.dst_device = None
        self.vm_mac_list = None
        self.mac_addrs_left = generator_config.mac_addrs_left
        self.mac_addrs_right = generator_config.mac_addrs_right
        self.__prep_interfaces(generator_config)

    def to_json(self):
        return dict(self.generator_config)

    def set_vm_mac_list(self, vm_mac_list):
        self.src_device.set_vm_mac_list(vm_mac_list[0])
        self.dst_device.set_vm_mac_list(vm_mac_list[1])

    @staticmethod
    def __match_generator_profile(traffic_generator, generator_profile):
        generator_config = AttrDict(traffic_generator)
        generator_config.pop('default_profile')
        generator_config.pop('generator_profile')
        matching_profile = [profile for profile in traffic_generator.generator_profile if
                            profile.name == generator_profile]
        if len(matching_profile) != 1:
            raise Exception('Traffic generator profile not found: ' + generator_profile)

        generator_config.update(matching_profile[0])

        return generator_config

    def __prep_interfaces(self, generator_config):
        src_config = {
            'chain_count': self.service_chain_count,
            'flow_count': self.flow_count / 2,
            'ip': generator_config.ip_addrs[0],
            'ip_addrs_step': self.ip_addrs_step,
            'gateway_ip': self.gateway_ips[0],
            'gateway_ip_addrs_step': self.gateway_ip_addrs_step,
            'tg_gateway_ip': generator_config.tg_gateway_ip_addrs[0],
            'tg_gateway_ip_addrs_step': self.tg_gateway_ip_addrs_step,
            'udp_src_port': generator_config.udp_src_port,
            'udp_dst_port': generator_config.udp_dst_port,
            'vlan_tagging': self.vlan_tagging,
            'dst_mac': generator_config.mac_addrs_left
        }
        dst_config = {
            'chain_count': self.service_chain_count,
            'flow_count': self.flow_count / 2,
            'ip': generator_config.ip_addrs[1],
            'ip_addrs_step': self.ip_addrs_step,
            'gateway_ip': self.gateway_ips[1],
            'gateway_ip_addrs_step': self.gateway_ip_addrs_step,
            'tg_gateway_ip': generator_config.tg_gateway_ip_addrs[1],
            'tg_gateway_ip_addrs_step': self.tg_gateway_ip_addrs_step,
            'udp_src_port': generator_config.udp_src_port,
            'udp_dst_port': generator_config.udp_dst_port,
            'vlan_tagging': self.vlan_tagging,
            'dst_mac': generator_config.mac_addrs_right
        }

        self.src_device = Device(**dict(src_config, **generator_config.interfaces[0]))
        self.dst_device = Device(**dict(dst_config, **generator_config.interfaces[1]))
        self.src_device.set_destination(self.dst_device)
        self.dst_device.set_destination(self.src_device)

        if self.service_chain == ChainType.EXT and not self.no_arp \
                and self.src_device.ip_range_overlaps():
            raise Exception('Overlapping IP address ranges src=%s dst=%d flows=%d' %
                            self.src_device.ip,
                            self.dst_device.ip,
                            self.flow_count)

    @property
    def devices(self):
        return [self.src_device, self.dst_device]

    @property
    def vlans(self):
        return [self.src_device.vtep_vlan, self.dst_device.vtep_vlan]

    @property
    def ports(self):
        return [self.src_device.port, self.dst_device.port]

    @property
    def switch_ports(self):
        return [self.src_device.switch_port, self.dst_device.switch_port]

    @property
    def pcis(self):
        return [self.src_device.pci, self.dst_device.pci]


class TrafficGeneratorFactory(object):
    def __init__(self, config):
        self.config = config

    def get_tool(self):
        return self.config.generator_config.tool

    def get_generator_client(self):
        tool = self.get_tool().lower()
        if tool == 'trex':
            from traffic_gen import trex
            return trex.TRex(self.config)
        elif tool == 'dummy':
            from traffic_gen import dummy
            return dummy.DummyTG(self.config)
        return None

    def list_generator_profile(self):
        return [profile.name for profile in self.config.traffic_generator.generator_profile]

    def get_generator_config(self, generator_profile):
        return RunningTrafficProfile(self.config, generator_profile)

    def get_matching_profile(self, traffic_profile_name):
        matching_profile = [profile for profile in self.config.traffic_profile if
                            profile.name == traffic_profile_name]

        if len(matching_profile) > 1:
            raise Exception('Multiple traffic profiles with the same name found.')
        elif not matching_profile:
            raise Exception('No traffic profile found.')

        return matching_profile[0]

    def get_frame_sizes(self, traffic_profile):
        matching_profile = self.get_matching_profile(traffic_profile)
        return matching_profile.l2frame_size


class TrafficClient(object):
    PORTS = [0, 1]

    def __init__(self, config, notifier=None, skip_sleep=False):
        generator_factory = TrafficGeneratorFactory(config)
        self.gen = generator_factory.get_generator_client()
        self.tool = generator_factory.get_tool()
        self.config = config
        self.notifier = notifier
        self.interval_collector = None
        self.iteration_collector = None
        self.runner = TrafficRunner(self, self.config.duration_sec, self.config.interval_sec)
        if self.gen is None:
            raise TrafficClientException('%s is not a supported traffic generator' % self.tool)

        self.run_config = {
            'l2frame_size': None,
            'duration_sec': self.config.duration_sec,
            'bidirectional': True,
            'rates': []  # to avoid unsbuscriptable-obj warning
        }
        self.current_total_rate = {'rate_percent': '10'}
        if self.config.single_run:
            self.current_total_rate = utils.parse_rate_str(self.config.rate)
        # UT with dummy TG can bypass all sleeps
        self.skip_sleep = skip_sleep

    def set_macs(self):
        for mac, device in zip(self.gen.get_macs(), self.config.generator_config.devices):
            device.set_mac(mac)

    def start_traffic_generator(self):
        self.gen.init()
        self.gen.connect()

    def setup(self):
        self.gen.set_mode()
        self.gen.config_interface()
        self.gen.clear_stats()

    def get_version(self):
        return self.gen.get_version()

    def ensure_end_to_end(self):
        """
        Ensure traffic generator receives packets it has transmitted.
        This ensures end to end connectivity and also waits until VMs are ready to forward packets.

        VMs that are started and in active state may not pass traffic yet. It is imperative to make
        sure that all VMs are passing traffic in both directions before starting any benchmarking.
        To verify this, we need to send at a low frequency bi-directional packets and make sure
        that we receive all packets back from all VMs. The number of flows is equal to 2 times
        the number of chains (1 per direction) and we need to make sure we receive packets coming
        from exactly 2 x chain count different source MAC addresses.

        Example:
            PVP chain (1 VM per chain)
            N = 10 (number of chains)
            Flow count = 20 (number of flows)
            If the number of unique source MAC addresses from received packets is 20 then
            all 10 VMs 10 VMs are in operational state.
        """
        LOG.info('Starting traffic generator to ensure end-to-end connectivity')
        rate_pps = {'rate_pps': str(self.config.service_chain_count * 1)}
        self.gen.create_traffic('64', [rate_pps, rate_pps], bidirectional=True, latency=False)

        # ensures enough traffic is coming back
        retry_count = (self.config.check_traffic_time_sec +
                       self.config.generic_poll_sec - 1) / self.config.generic_poll_sec
        mac_addresses = set()
        ln = 0
        for it in xrange(retry_count):
            self.gen.clear_stats()
            self.gen.start_traffic()
            self.gen.start_capture()
            LOG.info('Waiting for packets to be received back... (%d / %d)', it + 1, retry_count)
            if not self.skip_sleep:
                time.sleep(self.config.generic_poll_sec)
            self.gen.stop_traffic()
            self.gen.fetch_capture_packets()
            self.gen.stop_capture()

            for packet in self.gen.packet_list:
                mac_addresses.add(packet['binary'][6:12])
                if ln != len(mac_addresses):
                    ln = len(mac_addresses)
                    LOG.info('Flows passing traffic %d / %d', ln,
                             self.config.service_chain_count * 2)
                if len(mac_addresses) == self.config.service_chain_count * 2:
                    LOG.info('End-to-end connectivity ensured')
                    return

            if not self.skip_sleep:
                time.sleep(self.config.generic_poll_sec)

        raise TrafficClientException('End-to-end connectivity cannot be ensured')

    def ensure_arp_successful(self):
        if not self.gen.resolve_arp():
            raise TrafficClientException('ARP cannot be resolved')

    def set_traffic(self, frame_size, bidirectional):
        self.run_config['bidirectional'] = bidirectional
        self.run_config['l2frame_size'] = frame_size
        self.run_config['rates'] = [self.get_per_direction_rate()]
        if bidirectional:
            self.run_config['rates'].append(self.get_per_direction_rate())
        else:
            unidir_reverse_pps = int(self.config.unidir_reverse_traffic_pps)
            if unidir_reverse_pps > 0:
                self.run_config['rates'].append({'rate_pps': str(unidir_reverse_pps)})
        # Fix for [NFVBENCH-67], convert the rate string to PPS
        for idx, rate in enumerate(self.run_config['rates']):
            if 'rate_pps' not in rate:
                self.run_config['rates'][idx] = {'rate_pps': self.__convert_rates(rate)['rate_pps']}

        self.gen.clear_streamblock()
        self.gen.create_traffic(frame_size, self.run_config['rates'], bidirectional, latency=True)

    def modify_load(self, load):
        self.current_total_rate = {'rate_percent': str(load)}
        rate_per_direction = self.get_per_direction_rate()

        self.gen.modify_rate(rate_per_direction, False)
        self.run_config['rates'][0] = rate_per_direction
        if self.run_config['bidirectional']:
            self.gen.modify_rate(rate_per_direction, True)
            self.run_config['rates'][1] = rate_per_direction

    def get_ndr_and_pdr(self):
        dst = 'Bidirectional' if self.run_config['bidirectional'] else 'Unidirectional'
        targets = {}
        if self.config.ndr_run:
            LOG.info('*** Searching NDR for %s (%s)...', self.run_config['l2frame_size'], dst)
            targets['ndr'] = self.config.measurement.NDR
        if self.config.pdr_run:
            LOG.info('*** Searching PDR for %s (%s)...', self.run_config['l2frame_size'], dst)
            targets['pdr'] = self.config.measurement.PDR

        self.run_config['start_time'] = time.time()
        self.interval_collector = IntervalCollector(self.run_config['start_time'])
        self.interval_collector.attach_notifier(self.notifier)
        self.iteration_collector = IterationCollector(self.run_config['start_time'])
        results = {}
        self.__range_search(0.0, 200.0, targets, results)

        results['iteration_stats'] = {
            'ndr_pdr': self.iteration_collector.get()
        }

        if self.config.ndr_run:
            LOG.info('NDR load: %s', results['ndr']['rate_percent'])
            results['ndr']['time_taken_sec'] = \
                results['ndr']['timestamp_sec'] - self.run_config['start_time']
            if self.config.pdr_run:
                LOG.info('PDR load: %s', results['pdr']['rate_percent'])
                results['pdr']['time_taken_sec'] = \
                    results['pdr']['timestamp_sec'] - results['ndr']['timestamp_sec']
        else:
            LOG.info('PDR load: %s', results['pdr']['rate_percent'])
            results['pdr']['time_taken_sec'] = \
                results['pdr']['timestamp_sec'] - self.run_config['start_time']
        return results

    def __get_dropped_rate(self, result):
        dropped_pkts = result['rx']['dropped_pkts']
        total_pkts = result['tx']['total_pkts']
        if not total_pkts:
            return float('inf')
        return float(dropped_pkts) / total_pkts * 100

    def get_stats(self):
        stats = self.gen.get_stats()
        retDict = {'total_tx_rate': stats['total_tx_rate']}
        for port in self.PORTS:
            retDict[port] = {'tx': {}, 'rx': {}}

        tx_keys = ['total_pkts', 'total_pkt_bytes', 'pkt_rate', 'pkt_bit_rate']
        rx_keys = tx_keys + ['dropped_pkts']

        for port in self.PORTS:
            for key in tx_keys:
                retDict[port]['tx'][key] = int(stats[port]['tx'][key])
            for key in rx_keys:
                try:
                    retDict[port]['rx'][key] = int(stats[port]['rx'][key])
                except ValueError:
                    retDict[port]['rx'][key] = 0
            retDict[port]['rx']['avg_delay_usec'] = cast_integer(
                stats[port]['rx']['avg_delay_usec'])
            retDict[port]['rx']['min_delay_usec'] = cast_integer(
                stats[port]['rx']['min_delay_usec'])
            retDict[port]['rx']['max_delay_usec'] = cast_integer(
                stats[port]['rx']['max_delay_usec'])
            retDict[port]['drop_rate_percent'] = self.__get_dropped_rate(retDict[port])

        ports = sorted(retDict.keys())
        if self.run_config['bidirectional']:
            retDict['overall'] = {'tx': {}, 'rx': {}}
            for key in tx_keys:
                retDict['overall']['tx'][key] = \
                    retDict[ports[0]]['tx'][key] + retDict[ports[1]]['tx'][key]
            for key in rx_keys:
                retDict['overall']['rx'][key] = \
                    retDict[ports[0]]['rx'][key] + retDict[ports[1]]['rx'][key]
            total_pkts = [retDict[ports[0]]['rx']['total_pkts'],
                          retDict[ports[1]]['rx']['total_pkts']]
            avg_delays = [retDict[ports[0]]['rx']['avg_delay_usec'],
                          retDict[ports[1]]['rx']['avg_delay_usec']]
            max_delays = [retDict[ports[0]]['rx']['max_delay_usec'],
                          retDict[ports[1]]['rx']['max_delay_usec']]
            min_delays = [retDict[ports[0]]['rx']['min_delay_usec'],
                          retDict[ports[1]]['rx']['min_delay_usec']]
            retDict['overall']['rx']['avg_delay_usec'] = utils.weighted_avg(total_pkts, avg_delays)
            retDict['overall']['rx']['min_delay_usec'] = min(min_delays)
            retDict['overall']['rx']['max_delay_usec'] = max(max_delays)
            for key in ['pkt_bit_rate', 'pkt_rate']:
                for dirc in ['tx', 'rx']:
                    retDict['overall'][dirc][key] /= 2.0
        else:
            retDict['overall'] = retDict[ports[0]]
        retDict['overall']['drop_rate_percent'] = self.__get_dropped_rate(retDict['overall'])
        return retDict

    def __convert_rates(self, rate):
        return utils.convert_rates(self.run_config['l2frame_size'],
                                   rate,
                                   self.config.generator_config.intf_speed)

    def __ndr_pdr_found(self, tag, load):
        rates = self.__convert_rates({'rate_percent': load})
        self.iteration_collector.add_ndr_pdr(tag, rates['rate_pps'])
        last_stats = self.iteration_collector.peek()
        self.interval_collector.add_ndr_pdr(tag, last_stats)

    def __format_output_stats(self, stats):
        for key in self.PORTS + ['overall']:
            interface = stats[key]
            stats[key] = {
                'tx_pkts': interface['tx']['total_pkts'],
                'rx_pkts': interface['rx']['total_pkts'],
                'drop_percentage': interface['drop_rate_percent'],
                'drop_pct': interface['rx']['dropped_pkts'],
                'avg_delay_usec': interface['rx']['avg_delay_usec'],
                'max_delay_usec': interface['rx']['max_delay_usec'],
                'min_delay_usec': interface['rx']['min_delay_usec'],
            }

        return stats

    def __targets_found(self, rate, targets, results):
        for tag, target in targets.iteritems():
            LOG.info('Found %s (%s) load: %s', tag, target, rate)
            self.__ndr_pdr_found(tag, rate)
            results[tag]['timestamp_sec'] = time.time()

    def __range_search(self, left, right, targets, results):
        '''Perform a binary search for a list of targets inside a [left..right] range or rate

        left    the left side of the range to search as a % the line rate (100 = 100% line rate)
                indicating the rate to send on each interface
        right   the right side of the range to search as a % of line rate
                indicating the rate to send on each interface
        targets a dict of drop rates to search (0.1 = 0.1%), indexed by the DR name or "tag"
                ('ndr', 'pdr')
        results a dict to store results
        '''
        if not targets:
            return
        LOG.info('Range search [%s .. %s] targets: %s', left, right, targets)

        # Terminate search when gap is less than load epsilon
        if right - left < self.config.measurement.load_epsilon:
            self.__targets_found(left, targets, results)
            return

        # Obtain the average drop rate in for middle load
        middle = (left + right) / 2.0
        try:
            stats, rates = self.__run_search_iteration(middle)
        except STLError:
            LOG.exception("Got exception from traffic generator during binary search")
            self.__targets_found(left, targets, results)
            return
        # Split target dicts based on the avg drop rate
        left_targets = {}
        right_targets = {}
        for tag, target in targets.iteritems():
            if stats['overall']['drop_rate_percent'] <= target:
                # record the best possible rate found for this target
                results[tag] = rates
                results[tag].update({
                    'load_percent_per_direction': middle,
                    'stats': self.__format_output_stats(dict(stats)),
                    'timestamp_sec': None
                })
                right_targets[tag] = target
            else:
                # initialize to 0 all fields of result for
                # the worst case scenario of the binary search (if ndr/pdr is not found)
                if tag not in results:
                    results[tag] = dict.fromkeys(rates, 0)
                    empty_stats = self.__format_output_stats(dict(stats))
                    for key in empty_stats:
                        if isinstance(empty_stats[key], dict):
                            empty_stats[key] = dict.fromkeys(empty_stats[key], 0)
                        else:
                            empty_stats[key] = 0
                    results[tag].update({
                        'load_percent_per_direction': 0,
                        'stats': empty_stats,
                        'timestamp_sec': None
                    })
                left_targets[tag] = target

        # search lower half
        self.__range_search(left, middle, left_targets, results)

        # search upper half only if the upper rate does not exceed
        # 100%, this only happens when the first search at 100%
        # yields a DR that is < target DR
        if middle >= 100:
            self.__targets_found(100, right_targets, results)
        else:
            self.__range_search(middle, right, right_targets, results)

    def __run_search_iteration(self, rate):
        # set load
        self.modify_load(rate)

        # poll interval stats and collect them
        for stats in self.run_traffic():
            self.interval_collector.add(stats)
            time_elapsed_ratio = self.runner.time_elapsed() / self.run_config['duration_sec']
            if time_elapsed_ratio >= 1:
                self.cancel_traffic()
        self.interval_collector.reset()

        # get stats from the run
        stats = self.runner.client.get_stats()
        current_traffic_config = self.get_traffic_config()
        warning = self.compare_tx_rates(current_traffic_config['direction-total']['rate_pps'],
                                        stats['total_tx_rate'])
        if warning is not None:
            stats['warning'] = warning

        # save reliable stats from whole iteration
        self.iteration_collector.add(stats, current_traffic_config['direction-total']['rate_pps'])
        LOG.info('Average drop rate: %f', stats['overall']['drop_rate_percent'])

        return stats, current_traffic_config['direction-total']

    @staticmethod
    def log_stats(stats):
        report = {
            'datetime': str(datetime.now()),
            'tx_packets': stats['overall']['tx']['total_pkts'],
            'rx_packets': stats['overall']['rx']['total_pkts'],
            'drop_packets': stats['overall']['rx']['dropped_pkts'],
            'drop_rate_percent': stats['overall']['drop_rate_percent']
        }
        LOG.info('TX: %(tx_packets)d; '
                 'RX: %(rx_packets)d; '
                 'Dropped: %(drop_packets)d; '
                 'Drop rate: %(drop_rate_percent).4f%%',
                 report)

    def run_traffic(self):
        stats = self.runner.run()
        while self.runner.is_running:
            self.log_stats(stats)
            yield stats
            stats = self.runner.poll_stats()
            if stats is None:
                return
        self.log_stats(stats)
        LOG.info('Drop rate: %f', stats['overall']['drop_rate_percent'])
        yield stats

    def cancel_traffic(self):
        self.runner.stop()

    def get_interface(self, port_index, stats):
        port = self.gen.port_handle[port_index]
        tx, rx = 0, 0
        if stats and port in stats:
            tx, rx = int(stats[port]['tx']['total_pkts']), int(stats[port]['rx']['total_pkts'])
        return Interface('traffic-generator', self.tool.lower(), tx, rx)

    def get_traffic_config(self):
        config = {}
        load_total = 0.0
        bps_total = 0.0
        pps_total = 0.0
        for idx, rate in enumerate(self.run_config['rates']):
            key = 'direction-forward' if idx == 0 else 'direction-reverse'
            config[key] = {
                'l2frame_size': self.run_config['l2frame_size'],
                'duration_sec': self.run_config['duration_sec']
            }
            config[key].update(rate)
            config[key].update(self.__convert_rates(rate))
            load_total += float(config[key]['rate_percent'])
            bps_total += float(config[key]['rate_bps'])
            pps_total += float(config[key]['rate_pps'])
        config['direction-total'] = dict(config['direction-forward'])
        config['direction-total'].update({
            'rate_percent': load_total,
            'rate_pps': cast_integer(pps_total),
            'rate_bps': bps_total
        })

        return config

    def get_run_config(self, results):
        """Returns configuration which was used for the last run."""
        r = {}
        for idx, key in enumerate(["direction-forward", "direction-reverse"]):
            tx_rate = results["stats"][idx]["tx"]["total_pkts"] / self.config.duration_sec
            rx_rate = results["stats"][idx]["rx"]["total_pkts"] / self.config.duration_sec
            r[key] = {
                "orig": self.__convert_rates(self.run_config['rates'][idx]),
                "tx": self.__convert_rates({'rate_pps': tx_rate}),
                "rx": self.__convert_rates({'rate_pps': rx_rate})
            }

        total = {}
        for direction in ['orig', 'tx', 'rx']:
            total[direction] = {}
            for unit in ['rate_percent', 'rate_bps', 'rate_pps']:
                total[direction][unit] = sum([float(x[direction][unit]) for x in r.values()])

        r['direction-total'] = total
        return r

    @staticmethod
    def compare_tx_rates(required, actual):
        threshold = 0.9
        are_different = False
        try:
            if float(actual) / required < threshold:
                are_different = True
        except ZeroDivisionError:
            are_different = True

        if are_different:
            msg = "WARNING: There is a significant difference between requested TX rate ({r}) " \
                  "and actual TX rate ({a}). The traffic generator may not have sufficient CPU " \
                  "to achieve the requested TX rate.".format(r=required, a=actual)
            LOG.info(msg)
            return msg

        return None

    def get_per_direction_rate(self):
        divisor = 2 if self.run_config['bidirectional'] else 1
        if 'rate_percent' in self.current_total_rate:
            # don't split rate if it's percentage
            divisor = 1

        return utils.divide_rate(self.current_total_rate, divisor)

    def close(self):
        try:
            self.gen.stop_traffic()
        except Exception:
            pass
        self.gen.clear_stats()
        self.gen.cleanup()