sniffer.py

#!/usr/bin/python3

import sys
import getopt
import pcapy
from impacket.ImpactDecoder import EthDecoder


dev = "enp3s0f1"
filter = "arp"
decoder = EthDecoder()

# This function will be called for every packet
# and just print it
def handle_packet(hdr, data):
    print(decoder.decode(data))


def usage():
    print(sys.argv[0] + " -i <dev> -f <pcap_filter>")
    sys.exit(1)

# Parsing parameter
try:
    cmd_opts = "f:i:"
    opts, args = getopt.getopt(sys.argv[1:], cmd_opts)
except getopt.GetoptError:
    usage()

for opt in opts:
    if opt[0] == "-f":
        filter = opt[1]
    elif opt[0] == "-i":
        dev = opt[1]
    else:
        usage()

# Open device in promisc mode
pcap = pcapy.open_live(dev, 1500, 0, 100)

# Set pcap filter
pcap.setfilter(filter)

# Start sniffing
pcap.loop(0, handle_packet)