Scan TCP ports on a network with Python

scanner.py

# -*- coding: utf-8 -*-
"""
@author: Ólafur Aron Jóhannsson
@email: [email protected]
"""

import optparse, nmap, re
from socket import *
from threading import *

# chillax the thread
screenLock = Semaphore(value=1)

# nmap lib 
def nmapScan(tgtHost, tgtPort):
    nmScan = nmap.PortScanner()
    nmScan.scan(tgtHost, tgtPort)
    state = nmScan[tgtHost]['tcp'][int(tgtPort)]['state']
    
    try:
        name = gethostbyaddr(tgtHost)[0]
        if name is not None:
            print 'Scanning host: {0}'.format(name)
    except: 
        pass
    
    print '[*] {0} tcp/{1} {2}'.format(tgtHost, tgtPort, state)
    

def connScan(tgtHost, tgtPort):
    try:
        connSkt = socket(AF_INET, SOCK_STREAM)
        connSkt.connect((tgtHost, tgtPort))
	# garbage data
        connSkt.send('vi')
        results = connSkt.recv(128)

        screenLock.acquire()        
        
        print '[+] %d/tcp open' % tgtPort
        print '[+] ' + str(results)
    except:
        screenLock.acquire()
        print '[-] %d/tcp closed ' % tgtPort
    finally:
        screenLock.release()
        connSkt.close()
        
def portScan(tgtHost, tgtPorts):
    try:
        tgtIP = gethostbyname(tgtHost)
    except:
        print "[-] Cannot resolve '%s': Unknown host " % tgtHost
        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>')
    
    #options
    parser.add_option('-H', dest='tgtHost', type='string', help='specify target host')
    parser.add_option('-p', dest='tgtPort', type='string', help='specify target port')
    
    (options, args) = parser.parse_args()
    tgtHost = options.tgtHost
    tgtPorts = str(options.tgtPort).split(',')
    
    if (tgtHost == None) | (tgtPorts[0] == None):
        print '[-] You must specify a target host and port[s]'
        print parser.usage
        exit(0)
    
    
    # use nmap if we have a valid IP(add support to get hostaddr and use portScan as fallback)
    reip = u'\\b\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\b'
    ip = ''

    if re.match(reip, tgtHost) is not None:
        ip = tgtHost
    else:
        ip = gethostbyname(tgtHost)
                
    # after nmap lib, portscan and connscan is kinda useless
    for tgtPort in tgtPorts:
            nmapScan(ip, tgtPort)
            
            
if __name__ == '__main__':
    main()