import netmap

import time

import struct

import select

import argparse # program argument parsing

def build_packet():

fmt = '!6s6sH' + '46s'

return struct.pack(fmt, '\xff'*6, '\x00'*6, 0x0800, '\x00'*50)

parser = argparse.ArgumentParser(description = 'Minimal, high-performance packet '\

'generator written in Python using '\

'the netmap API',

epilog = 'Press Ctrl-C to stop')

parser.add_argument('-i', '--interface', help = 'the interface to register with netmap; '

'can be in the form <OSNAME> or <VALENAME>, where '

'OSNAME is the O.S. name for a network interface (e.g. "eth0"), '

'<VALENAME> is a valid VALE port name (e.g. "vale18:2")',

default = 'vale0:0')

args = parser.parse_args()

pkt = build_packet()

print("Opening interface %s" % (args.interface))

nm = netmap.Netmap()

nm.open()

nfd = nm.getfd()

nm.if_name = args.interface

nm.register()

time.sleep(1)

txr = nm.transmit_rings[0]

num_slots = txr.num_slots

for i in range(num_slots):

txr.slots[i].buf[0:len(pkt)] = pkt

txr.slots[i].len = len(pkt)

print("Starting transmission, press Ctrl-C to stop")

cnt = 0 # packet counter

batch = 256

poller = select.poll()

poller.register(nfd, select.POLLOUT)

t_start = time.time()

try:

cur = txr.cur

while 1:

ready_list = poller.poll(2)

if len(ready_list) == 0:

print("Timeout occurred")

break;

n = txr.tail - cur # avail

if n < 0:

n += num_slots

if n > batch:

n = batch

cur += n

if cur >= num_slots:

cur -= num_slots

txr.cur = txr.head = cur # lazy update txr.cur and txr.head

nm.txsync()

cnt += n

except KeyboardInterrupt:

pass

t_end = time.time()

rate = 0.001 * cnt / (t_end - t_start)

unit = 'K'

if rate > 1000:

rate /= 1000.0

unit = 'M'

print("\nPackets sent: %s, Avg rate %6.3f %spps" % (cnt, rate, unit))

nm.close()