send.py

#!/usr/bin/env python3
import socket
import sys

from scapy.all import (
    IP,
    UDP,
    Ether,
    Packet,
    bind_layers,
    get_if_hwaddr,
    get_if_list,
    sendp
)
from scapy.fields import *


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

class SourceRoute(Packet):
   fields_desc = [ BitField("bos", 0, 1),
                   BitField("port", 0, 15)]

bind_layers(Ether, SourceRoute, type=0x1234)
bind_layers(SourceRoute, SourceRoute, bos=0)
bind_layers(SourceRoute, IP, bos=1)

def main():

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

    addr = socket.gethostbyname(sys.argv[1])
    iface = get_if()
    print("sending on interface %s to %s" % (iface, str(addr)))

    while True:
        print()
        s = str(input('Type space separated port nums '
                          '(example: "2 3 2 2 1") or "q" to quit: '))
        if s == "q":
            break;
        print()

        i = 0
        pkt =  Ether(src=get_if_hwaddr(iface), dst='ff:ff:ff:ff:ff:ff');
        for p in s.split(" "):
            try:
                pkt = pkt / SourceRoute(bos=0, port=int(p))
                i = i+1
            except ValueError:
                pass
        if pkt.haslayer(SourceRoute):
            pkt.getlayer(SourceRoute, i).bos = 1

        pkt = pkt / IP(dst=addr) / UDP(dport=4321, sport=1234)
        pkt.show2()
        sendp(pkt, iface=iface, verbose=False)

    #pkt = pkt / SourceRoute(bos=0, port=2) / SourceRoute(bos=0, port=3);
    #pkt = pkt / SourceRoute(bos=0, port=2) / SourceRoute(bos=0, port=2);
    #pkt = pkt / SourceRoute(bos=1, port=1)


if __name__ == '__main__':
    main()