Python通过pysnmp和nmap获取netstat

最近在研究snmp协议，用Python的pysnmp模块编写了一段可以获取snmp协议中netstat的脚本，了解了一些pysnmp的用法。

0x01 安装pysnmp

>>> pip install pysnmp>>> import pysnmp()

0x02 pysnmp

def snmpget(printer_ip):    cg = cmdgen.CommandGenerator() ##获得CommandGenerator对象     errorIndication, errorStatus, errorIndex, varBinds = cg.getCmd(        cmdgen.CommunityData('server', 'public', 1),  ## 扫描名称，扫描方式，版本号        cmdgen.UdpTransportTarget((printer_ip, 161)), ## 扫描IP，扫描端口        '.1.3.6.1.2.1.4.20.1.3.192.168.0.69'          ## OID，此处表示获取子网掩码    )    subnet_mask = str(varBinds[0]).split('=')[1].strip() ##结果存在varBind()中    return subnet_mask 

0x03 nmap

Python的nmap的使用方式与nmap的参数一样，初始化后直接输入语句即可。返回值为多重字典组成的json数据，使用在线json转换工具即可找到最终要找的目标值。

def Scan():    nm = nmap.PortScanner()    result = nm.scan(hosts=target, arguments="-sU -p 161 --script=snmp-netstat")    totle_list = str(result['scan'][target]['udp'][161]['script']['snmp-netstat'])    try:        if result['scan'][target]['udp'][161]['script']['snmp-netstat'] :            f = open('test.txt', 'a+')            f.write(time.strftime('%Y-%m-%d: %I:%M',time.localtime(time.time())))            f.write(str(result['scan'][target]['udp'][161]['script']['snmp-netstat']))            f.close()    except (IOError, KeyError):        pass    pagehandler.close()    return get_target_list(totle_list)

最后附上完整代码，这个脚本用来测试内网设备时候链接了外网：

import nmapimport timeimport urllibfrom pysnmp.entity.rfc3413.oneliner import cmdgendef snmpget(printer_ip):    cg = cmdgen.CommandGenerator() ##获得CommandGenerator对象     errorIndication, errorStatus, errorIndex, varBinds = cg.getCmd(        cmdgen.CommunityData('server', 'public', 1),        cmdgen.UdpTransportTarget((printer_ip, 161)),        '.1.3.6.1.2.1.4.20.1.3.192.168.0.69'    )    subnet_mask = str(varBinds[0]).split('=')[1].strip()    return subnet_maskdef Scan(target):    nm = nmap.PortScanner()    result = nm.scan(hosts=target, arguments="-sU -p 161 --script=snmp-netstat")    scan_target = 'http://' + target    pagehandler = urllib.urlopen(scan_target)    totle_list = str(result['scan'][target]['udp'][161]['script']['snmp-netstat'])    try:        if result['scan'][target]['udp'][161]['script']['snmp-netstat'] :            f = open('test.txt', 'a+')            f.write(time.strftime('%Y-%m-%d: %I:%M',time.localtime(time.time())))            f.write(str(result['scan'][target]['udp'][161]['script']['snmp-netstat']))            f.close()    except (IOError, KeyError):        pass    pagehandler.close()    return get_target_list(totle_list)def get_target_list(totle_list):    now_addr = ''    check_ips = []    flag = 0    line = ''    lines = []    for i in totle_list:        if i != '\n':            line = line + i        else:            lines.append(line)            line = ''    for i in range(len(lines)):        if lines[i]:            for j in range(28,45):                try:                    now_addr += lines[i][j]                except IndexError:                    continue            check_ips.append(now_addr.split(':')[0])            now_addr = ''    return check_ipsdef compare(subnet, printer_ip, target_list):    flag = 1    target_temp = []    printer_mask = [0,0,0,0]    target_mask_list = []    subnet_mask = subnet.split('.')    printer = printer_ip.split('.')     for i in range(4):        printer_mask[i] = int(printer[i]) & int(subnet_mask[i])     for i in range(len(target_list)):        target_mask = target_list[i].split('.')        for i in range(len(target_mask)):            try:                target = int(target_mask[i]) & int(subnet_mask[i])                target_temp.append(target)            except (ValueError, IndexError):                continue        target_mask_list.append(target_temp)        target_temp = []    print target_mask_list, subnet_mask, printer_mask,target_list    for i in range(len(target_mask_list)):        if printer_mask != target_mask_list[i] and target_list[i]!='*' and target_list[i] != '0.0.0.0':            print('Warning,target_ip:%s'%target_list[i])            flag = 0    if flag == 1:        print 'Safe'def main():    while True:        printer_ip = '192.168.0.69'        subnet_mask = snmpget(printer_ip)        target_list = Scan(printer_ip)        compare(subnet_mask, printer_ip, target_list)        time.sleep(300)if __name__ == '__main__':      main()