Zero rx stream stats in STL mode (while using vm in STLPktBuilder)

[Sergei Karimov]

Test case: i send 6 stream ( with different protocols ) to 1 interface in STL mode and then check RX stats  per stream.

If i not use vm in STLPktBuilder ,  i can get  rx_pckts stats per stream.

but when i use vm , all rx stats in streams = 0.

example python script :

```

# Example showing how to define stream for getting per flow statistics, and how to parse the received statistics

import stl_path

from trex_stl_lib.api import *

import subprocess

import json

import time

import pprint

def rx_example (tx_port, rx_port, burst_size, bw):

    print("\nGoing to inject {0} packets on port {1} - checking RX stats on port {2}\n".format(burst_size, tx_port, rx_port))

    # create client

    c = STLClient()

    passed = True

    

    try:

        vm = STLScVmRaw( [ STLVmFlowVar( 

#                                      min_value=1488, max_value=65300,

                                      min_value="16.0.0.1", max_value="16.0.0.5",

      size=4, 

      name="UDP_PORT"),                     

#                   STLVmWrFlowVar(fv_name="tuple.ip", pkt_offset= "IP.src" ),  

                   

   STLVmWrFlowVar(fv_name="UDP_PORT", pkt_offset= "IP.src" ),

                   STLVmFixIpv4(offset = "IP") # fix checksum              

           

                  ]

               )

        pkt = STLPktBuilder(pkt = "pcaps/snmp.pcap" )

#pkt2 = STLPktBuilder(pkt = "/tmp/v2.37/avl/http_browsin(.pcap")

pkt2 = STLPktBuilder(pkt = "pcaps/sipv2.pcap" )

pkt3 = STLPktBuilder(pkt = "pcaps/dns_port.pcap" )

pkt4 = STLPktBuilder(pkt = "pcaps/ISAKMP_sa_setup.cap" )

# pkt5 = STLPktBuilder(pkt = "pcaps/udpgmd.pcap", vm = vm)

pkt5 = STLPktBuilder(pkt = "pcaps/tftpv2.pcap")

pkt6 = STLPktBuilder(pkt = "pcaps/NTP_sync.pcap")

# pkt6 = STLPktBuilder(pkt = Ether()/IP(src="16.0.0.1",dst="48.0.0.1")/UDP(dport=12,sport=1025)/'a_aaaaaa')

        

s1 = STLStream(name = 'rx',

                       packet = pkt,

                       flow_stats = STLFlowStats(pg_id = 0),

mode = STLTXCont(percentage = 10))

        s2 = STLStream(name = 'rx2',

                       packet = pkt2,

                       flow_stats = STLFlowStats(pg_id = 2),

mode = STLTXCont(percentage = 10))

        s3 = STLStream(name = 'rx3',

                       packet = pkt3,

                       flow_stats = STLFlowStats(pg_id = 3),

mode = STLTXCont(percentage = 10))

        s4 = STLStream(name = 'rx4',

                       packet = pkt4,

                       flow_stats = STLFlowStats(pg_id = 4),

mode = STLTXCont(percentage = 10))

        s5 = STLStream(name = 'rx5',

                       packet = pkt5,

                       flow_stats = STLFlowStats(pg_id = 5),

mode = STLTXCont(pps = 4801))

        s6 = STLStream(name = 'rx6',

                       packet = pkt6,

                       flow_stats = STLFlowStats(pg_id = 6),

mode = STLTXSingleBurst(total_pkts = 100000, percentage = 10))

streams = [s1,s2 ,s3,s4, s5, s6]

        # connect to server

        c.connect()

        # prepare our ports

        c.reset(ports = [tx_port, rx_port])

        # add stream to port

        c.add_streams(streams, ports = [tx_port])

        rc = rx_iteration(c, tx_port, rx_port, s1.get_pkt_len())

        if not rc:

            passed = False

#print c.get_stats()

    except STLError as e:

        passed = False

        print(e)

    finally:

        c.disconnect()

    if passed:

        print("\nTest passed :-)\n")

    else:

        print("\nTest failed :-(\n")

# RX one iteration

def rx_iteration (c, tx_port, rx_port, pkt_len):

    ret = True

    c.clear_stats()

    c.start(ports = [tx_port],duration=500)

    c.wait_on_traffic(ports = [tx_port])

    global_flow_stats = c.get_pgid_stats()['flow_stats']

    print global_flow_stats

 #   print json.dumps(flow_stats, indent = 4)

    print "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"

#    print json.dumps(flow_stats2, indent = 4)

    print global_flow_stats.get(0)["rx_pkts"]

    print global_flow_stats.get(2)["rx_pkts"]

    print global_flow_stats.get(3)["rx_pkts"]

    print global_flow_stats.get(5)

# run the tests

rx_example(tx_port = 0, rx_port = 1, burst_size = 1000, bw = 40)

```