Python 端口扫描器

Question

I've been writing a little script to scan a host for a specific port range by choice and ran into some weird error while trying to test the custom range:

Traceback (most recent call last):
File "/root/Desktop/ScannerV1Beta.py", line 74, in <module>
   result = s.connect_ex((targetIP, i))

File "/usr/lib/python2.7/socket.py", line 224, in meth
   return getattr(self._sock,name)(*args)

File "/usr/lib/python2.7/socket.py", line 170, in _dummy
   raise error(EBADF, 'Bad file descriptor')

   socket.error: [Errno 9] Bad file descriptor

#!/usr/bin/env python

from socket import *


target = raw_input('Enter host or ip to scan: ')
targetIP = gethostbyname(target)
choice = raw_input('Please Choose the port range:\n (1) 1 - 1023 \n (2) 1024 - 5000 \n (3) 5000 - 10000 \n (c) custom \n ')
print 'Starting scan on host ', targetIP



if choice == '1':
    for i in range(1, 134):
        s = socket(AF_INET, SOCK_STREAM)

        result = s.connect_ex((targetIP, i))

        if(result == 0) :
            print 'Port %d: OPEN' % (i)
        else:
            print 'Port %d: CLOSED' % (i)
        s.close()

    for i in range(133, 1024):
        s = socket(AF_INET, SOCK_STREAM)

        result = s.connect_ex((targetIP, i))

        if(result == 0) :
            print 'Port %d: OPEN' % (i)
        else:
            print 'Port %d: CLOSED' % (i)

        s.close()



elif choice == '2':
    for i in range(1024, 5000):
        s = socket(AF_INET, SOCK_STREAM)

        result = s.connect_ex((targetIP, i))

        if(result == 0) :
            print 'Port %d: OPEN' % (i)
        else:
            print 'Port %d: CLOSED' % (i)

        s.close()

if choice == '3':
    for i in range(5000, 10000):
        s = socket(AF_INET, SOCK_STREAM)

        result = s.connect_ex((targetIP, i))

        if(result == 0) :
            print 'Port %d: OPEN' % (i)
        else:
            print 'Port %d: CLOSED' % (i)

        s.close()
if choice == 'c':
    firstPort = raw_input('Please specify starting Port: ')
    endPort = raw_input('Please specify ending Port(max 65535): ')
    endPort = int(endPort)
    firstPort = int(firstPort)
    s = socket(AF_INET, SOCK_STREAM)

    if firstPort in range(0, 65535):
        if endPort in range(0, 65535):
            for i in range(firstPort, endPort):
                result = s.connect_ex((targetIP, i))
                if(result == 0) :
                    print 'Port %d: OPEN' % (i)
                else:
                    print 'Port %d: CLOSED' % (i)
                s.close()
        else:
            print('Error: Ports not in range!!')
            s.close()
    else:
        print('Error:Ports not in range!!')
        s.close()

i know the way i handled and converted the chosen ports is not the best option but i was quite on a run there. What might be the possible cause for said errors?

Answer 1

In the last "for" you are closing socket, but don't creating new. Rewrite the last "for" cycle as:

for i in range(firstPort, endPort):
    s = socket(AF_INET, SOCK_STREAM)
    result = s.connect_ex((targetIP, i))
    if(result == 0) :
        print 'Port %d: OPEN' % (i)
    else:
        print 'Port %d: CLOSED' % (i)
    s.close()

Answer 2

portscanner

---

#!/usr/bin/python3
import socket
import os
import platform
def cls():
    if platform.system() == 'Linux':
      os.system("clear")
    else:
        os.system("cls")
def main():
    cls()
    print("---[ Port Scanner ]---\n")
    host = input("Enter Host: ")
    print("\n")
    ports = [21,22,23,25,80,111,443] # ports
    for port in ports:
       s = socket.socket()
       ch = s.connect_ex((host,port))
       if ch.status_code == 200:
         print(f"Port: {port} Open!")
       else:
           print(f"Port: {port} Filter!")
if __name__ == '__main__':
  try:
     main()
  except (KeyboardInterrupt,EOFError):
      print("\nStop !!!")
      exit()