send.py

#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0-only
# Reason-GPL: import-scapy

import socket
import sys
from time import sleep

from scapy.all import IP, UDP, Ether, get_if_hwaddr, get_if_list, sendp


def get_if():
    ifs=get_if_list()
    iface=None # "h1-eth0"
    for i in get_if_list():
        if "eth0" in i:
            iface=i
            break;
    if not iface:
        print("Cannot find eth0 interface")
        exit(1)
    return iface

def main():

    if len(sys.argv)<4:
        print('pass 2 arguments: <destination> "<message>" <duration>')
        exit(1)

    addr = socket.gethostbyname(sys.argv[1])
    iface = get_if()

    pkt = Ether(src=get_if_hwaddr(iface), dst="ff:ff:ff:ff:ff:ff") / IP(dst=addr, tos=1) / UDP(dport=4321, sport=1234) / sys.argv[2]
    pkt.show2()
    #hexdump(pkt)
    try:
      for i in range(int(sys.argv[3])):
        sendp(pkt, iface=iface)
        sleep(1)
    except KeyboardInterrupt:
        raise


if __name__ == '__main__':
    main()