dash.py

import pcapy
from impacket.ImpactDecoder import *
from impacket.ImpactPacket import *

# callback for received packets
def recv_pkts(hdr, data):
    packet = EthDecoder().decode(data)
    ip_hdr = packet.child()
    op_code = ip_hdr.get_ar_op()
    src_mac = ip_hdr.as_hrd(ip_hdr.get_ar_sha())
    dest_ip = ip_hdr.as_pro(ip_hdr.get_ar_spa())
    print "ARP Request from Device : " + str(src_mac)
    if dest_ip == '0.0.0.0' and op_code == 1 and src_mac == "your dash mac here":
        print "Hello from Dash"

if __name__ == "__main__":
    max_bytes = 1024
    promiscuous = 0 # every data packet transmitted can be received and read by a network adapter to which its connected
    read_timeout = 100 # in milliseconds
    pc = pcapy.open_live("en0", max_bytes, promiscuous, read_timeout)
    packet_limit = 10
    pc.setfilter("arp")

    try:
        pc.loop(packet_limit, recv_pkts) # capture packets
    except KeyboardInterrupt:
        pass