python 实现简单的端口扫描器

#coding=utf-8
import socket
import time
import sys
 
def portScanner(ip,port):
    server = (ip,port)
    sockfd = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    sockfd.settimeout(0.5)
    ret = sockfd.connect_ex(server)  #返回0则成功
    if not ret:
        sockfd.close()
        print '%s:%s is opened...' % (ip,port)
    else:
        sockfd.close()
        pass
    return ''
 
def ip2num(ip):
    lp = [int(x) for x in ip.split('.')]
    return lp[0] << 24 | lp[1] << 16 | lp[2] << 8 |lp[3]
 
def num2ip(num):
    ip = ['','','','']
    ip[3] = (num & 0xff)
    ip[2] = (num & 0xff00) >> 8
    ip[1] = (num & 0xff0000) >> 16
    ip[0] = (num & 0xff000000) >> 24
    return '%s.%s.%s.%s' % (ip[0],ip[1],ip[2],ip[3])
 
def iprange(ip1,ip2):
    num1 = ip2num(ip1)
    num2 = ip2num(ip2)
    tmp = num2 - num1
    if tmp < 0:
        return None
    else:
        return num1,num2,tmp

def scanip(ip):
    port = 0
    res = ''
    while port < 65536:
        s=socket.socket()
        address = str(ip)
        try:
            s.connect((address,port))
            res = res + str(port) + '
'
            #print str(port) + ' is opening'
        except socket.error,e:
            pass
            #print str(port) + ' Not Opened'
        port = port + 1
    print res
 
if __name__ == '__main__':
    #输出运行时的时间
    print 'start time : %s' % time.ctime(time.time())
    #没有传入参数，打印使用方法
    if len(sys.argv) == 1:
        print 'Usage 1:scannerports.py startip endip port (get the specfic given opening port from startip to endip)'
        print 'Usage 2:scannerports.py destip (get all the opening ports from destip) '
        print 'Usage 3:scannerports.py startip endip (get all the opening ports from startip to endip)'
        sys.exit()
    #传入了一个参数ip，扫描这个ip打开的端口
    if len(sys.argv) == 2:
        ip = sys.argv[1]
        print str(ip) + ' is scanned...'
        #调用扫描端口方法
        scanip(ip)
    elif len(sys.argv) == 3:#扫描网段内所有ip所有端口
        res = ()
        startip = sys.argv[1]#网段起始ip
        endip = sys.argv[2]#网段结束ip
        res = iprange(startip,endip)#判断网段大小
        
        if not res:
            print 'endip must be bigger than startone'
            sys.exit()
        elif res[2] == 0:#只有一个ip
            print str(ip) + ' is scanned...'
            scanip(ip)
        else:#循环扫描网段中的每个ip
            startipn = ip2num(startip)
            for x in xrange(endip-startip+1):
                print str(ip) + ' is scanned...'
                startipnum = startipn + x
                scanip(num2ip(startipnum))#扫描ip的端口
    else:#扫描指定网段内的指定端口
        res = ()
        startip = sys.argv[1]#网段起始ip
        endip = sys.argv[2]#网段结束ip
        port = int(sys.argv[3])#指定端口
        res = iprange(startip,endip)#判断网段大小
        if not res:
            print 'endip must be bigger than startone'
            sys.exit()
        elif res[2] == 0:#只有一个ip
            portScanner(startip,port)
        else:#循环扫描网段中的每个ip
            startipn = ip2num(startip)
            for x in xrange(int(res[2])+1):
                startipnum = startipn + x
                portScanner(num2ip(startipnum),port)#扫描ip的指定端口
    print 'end time : %s' % time.ctime(time.time())#输出结束时间