scapy_icmp.py

#!/usr/bin/env python
#
# ping the network to look for inactive machines
# requires scapy-2.2.0 or better


import argparse
import time
import sched
from scapy.all import sr, srp, IP, UDP, ICMP, TCP, ARP, Ether
RUN_FREQUENCY = 10
scheduler = sched.scheduler(time.time, time.sleep)


def detect_inactive_hosts(scan_hosts):
    """ scan net to see if hosts are up or down
    use ranges like 192.168.2.2-4 see scapy docs """
    global scheduler
    scheduler.enter(RUN_FREQUENCY, 1, detect_inactive_hosts, (scan_hosts, ))
    inactive_hosts = []
    try:
        ans, unans = sr(IP(dst=scan_hosts)/ICMP(), retry=0, timeout=1)
        ans.summary(lambda(s,r) : r.sprintf("%IP.src% is alive"))
        for inactive in unans:
            print "%s is inactive" %inactive.dst
            inactive_hosts.append(inactive.dst)
        print "Total %d hosts are inactive" % (len(inactive_hosts))
    except KeyboardInterrupt:
        exit(0)

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description=' Python network utils')
    parser.add_argument('--scan-hosts', action="store", dest="scan_hosts",\
        required=True)
    given_args = parser.parse_args()
    scan_hosts = given_args.scan_hosts
    scheduler.enter(1, 1, detect_inactive_hosts, (scan_hosts, ))
    scheduler.run()