portscanner.py

import optparse
from socket import *
from threading import *

screenLock = Semaphore(value=1)

def connScan(tgtHost, tgtPort):
    try:
        connSkt = socket(AF_INET, SOCK_STREAM)
        connSkt.connect((tgtHost, tgtPort))
        connSkt.send('hello\r\n')
        
        results = connSkt.recv(100)
        screenLock.acquire()
        print('[+]' + str(tgtPort) + '/tcp open')
    except:
        screenLock.acquire()
        print('[+]' + str(tgtPort) + '/tcp closed')
    finally:
        screenLock.release()
        connSkt.close()
        
def portScan(tgtHost, tgtPorts):
    try:
        tgtIP = gethostbyname(tgtHost)
    except:
        print('[+] Cannot resolve ' + tgtHost + ': Unknown host')
        return
    try:
        tgtName = gethostbyaddr(tgtIP)
        print('\n[+] Scan Results for: '+ tgtName[0])
    except:
        print('\n[+] Scan Results for: '+ tgtIP)
        
    setdefaulttimeout(1)
    for tgtPort in tgtPorts:
        t = Thread(target=connScan, args=(tgtHost, int(tgtPort)))
        t.start()

def Main():
    parser = optparse.OptionParser('Usage %prog -H <target host>'+\
    '-p <target port>')
    parser.add_option('-H', dest='tgtHost', type='string', \
    help='specify target host')
    parser.add_option('-p', dest='tgtPort', type='string', \
    help='specify target port[s] separated by a comma')
    (option, args) = parser.parse_args()
    if (option.tgtHost == None) | (option.tgtPort == None):
        print (parser.usage)
        exit(0)
    else:
        tgtHost = options.tgtHost
        tgtPorts = str(options.tgtPort).split(',')
        
    portScan(tgtHost, tgtPorts)
    
if __name__ == '__main__':
    Main()