portscanner.py

#!/usr/bin/env python
# -*- encoding: utf-8 -*-

import argparse
import socket
import sys

def scan_ports(host, start_port, end_port):
    """ Scan remote hosts """
    #Create socket
    try:
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    except socket.error, err_msg:
        print 'Socket creation failed. Error code: ' + str(err_msg[0]) + \
        ' Error message: ' + err_msg[1]
        sys.exit()

    #Get IP of remote host
    try:
        remote_ip = socket.gethostbyname(host)
    except socket.error, error_msg:
        print error_msg
        sys.exit()

    #Scan ports
    print "Start scanning... "
    end_port += 1
    for port in range(start_port, end_port):
        try:
            ret = sock.connect_ex((remote_ip, port))
            if ret == 0:
                print 'Port ' + str(port) + ' is open'
            sock.close()
            sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        except socket.error:
            pass

if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Remote Port Scanner')
    parser.add_argument('--host', action="store", dest="host", default='localhost')
    parser.add_argument('--start-port', action="store", dest="start_port", default=1, type=int)
    parser.add_argument('--end-port', action="store", dest="end_port", default=100, type=int)

    #parse arguments
    given_args = parser.parse_args()
    host, start_port, end_port = given_args.host, given_args.start_port, given_args.end_port
    scan_ports(host, start_port, end_port)