network_scanner.py

import argparse
import csv
import datetime as dt
import os

import scapy.all as scapy


def check_outdir(outdir):
    if not os.path.exists(outdir):
        raise argparse.ArgumentTypeError(
            "the specified output directory '{}' doesn't exist".format(outdir)
        )
    if not os.path.isdir(outdir):
        raise argparse.ArgumentTypeError(
            "the specified output directory '{}' is not a directory".format(outdir)
        )
    return outdir


def get_args():
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "-t", "--target", required=True, help="Target IP Address/Adresses"
    )
    parser.add_argument(
        "-o", "--outdir", type=check_outdir, help="Output directory of the scan result",
    )
    args = parser.parse_args()

    return args


def scan(target):
    arp_req_frame = scapy.ARP(pdst=target)
    broadcast_eth_frame = scapy.Ether(dst="ff:ff:ff:ff:ff:ff")
    broadcast_eth_arp_req_frame = broadcast_eth_frame / arp_req_frame
    answered_list = scapy.srp(broadcast_eth_arp_req_frame, timeout=1, verbose=False)[0]

    scan_results = []
    for answer in answered_list:
        client_dict = {"ip": answer[1].psrc, "mac": answer[1].hwsrc}
        scan_results.append(client_dict)
    return scan_results


def display_result(scan_results):
    print(
        "-----------------------------------\nIP Address\tMAC Address\n-----------------------------------"
    )
    for result in scan_results:
        print("{}\t{}".format(result["ip"], result["mac"]))


def write_results(scan_results, outdir):
    timestamp = dt.datetime.now().strftime("%Y%m%d%H%M")
    filename = "scan_result_{}.csv".format(timestamp)
    filepath = os.path.join(outdir, filename)

    with open(filepath, "w") as fp:
        if len(scan_results):
            # if there's any scan result, write to the csv
            # otherwise just create the empty file
            writer = csv.DictWriter(fp, scan_results[0].keys())
            writer.writeheader()
            writer.writerows(scan_results)


if __name__ == "__main__":
    args = get_args()
    scan_results = scan(args.target)
    if args.outdir:
        # store the results in the specified output directory
        write_results(scan_results, args.outdir)
    else:
        # outdir not specified, print results to console
        display_result(scan_results)