测试用户所在环境的NAT设备类型(原创作品，转发请注出处)

#! /usr/bin/python

# -*- coding:utf-8 -*-

#

# @Version : 1.0

# @Time : 2018/4/1

# @Author : hejl

# @File : natchk.py

# @Summery : Detect client's local network on which type of NAT

'''

测试用户所在环境的NAT设备类型

NAT1: Full Cone

NAT2: Restricted Cone

NAT3: Port-Restricted Cone

NAT4: Symmetric

拓普模型:

两服务端 + 一客户端，服务端要求有有独立公网IP，至少一台，

客户端在要测试的网络环境机器上执行, 服务端的防火墙需放行相关的UDP端口

C(client)

＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿|＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿

1| ↑8 2| ↑7 ↑6 ↑9 10| ↑11

↓ | ↓ | | | | |

Server1 S1:P1 S1:P2 S1:P3 | | |

|----------------------------------------↑3 4 5 | ↓ |

Server2 +----------------------------------------------------→ S2:P1 -------------→ S2:P2 ------------→ S2:P3

序列图: (UDP响应无顺序性，6/7/8/9先后到达不影响)

c S1:P1 S1:P2 S1:P3 S2:P1 S2:P2 S2:P3

| | | | | | |

|---------->| 1 | | | | |

|-----------+----------->|2 | | | |

|<----------+------------| | | | |

|7 | | | | | |

| |------------+---------->|3 | | |

| |------------+-----------+-------------------->|4 | |

|6 | | | +----------->|5 |

|<----------+------------------------| | | |

|8 | | | | | |

|<----------+ | | | | |

| | | | | | |

<----------+------------+-----------+---------------------+------------| |

|9 | | | | | |

| | | | | | |

| | | | | | |

|-----------+------------+-----------+---------------------+------------+------------->|10

|<----------+------------+-----------+---------------------+------------+--------------|11

| | | | | | |

| | | | | | |

| | | | | | |

响应的rStep(程序内的标识响应的身份)与上面时序标号关系:

rStep1 <---> 8

rStep2 <---> 7

rStep3 <---> 3

rStep4 <---> 9

rStep5 <---> 11

传参:

s1: 服务端1

s2: 服务端2 [可选，没有时会降低准确度]

c: 客户端

运行环境注意:

此工具服务端和客户端都使本同一程序文件，服务端要求有两个公网IP(相应端口不能被防火墙拦截)，客户端要求能连通公网；

使用示例:

1. 获得natchk.py文件之后，修改程序开始处的服务器地址

s1_ip='第一台具备公网IP的机器' (本文件85行)

s2_ip='第二台具备公网IP的机器' (本文件90行)

2. 运行服务端程序

第一台上运行 python natchk.py s1

第二台上运行 python natchk.py s2

3. 在待检测的环境运行客户端程序

python natchk.py c

网络正常的话10内打印出检测结果

结果输出样式Test Summery: NAT3 Port Restricted

'''

import threading

import socket

import json

import sys

s1_ip='162.219.126.121' # you need modify here

s1_port1=17770 # listen and recv+resp

s1_port2=17771 # listen and recv+resp

s1_port3=18770 # sendto

s2_ip='xx.xx.xx.xx' # you need modify here

s2_port1=27770 # listen for s1 notify;

s2_port2=27771 # sendto

s2_port3=28770 # listen and recv+resp # check Symmetric (Last)

c_ip='0'

c_port=0

wait_timeout_ms = 5

def createUdpSock(ip, port):

us = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

if ip > 0 and port > 0:

us.bind( (ip,port) )

print("socket Bind to " + str(us.getsockname()) )

return us

def udpSendTo(us, serv, port, data):

strdata = json.dumps(data)

return us.sendto(strdata, (serv, port))

def udpRecvFrom(us, waitsec, count):

try:

datalst = []

us.settimeout(waitsec)

for i in range(count):

datalst.append(us.recvfrom(1024))

except socket.timeout, e:

pass

return datalst

def loadJsonStr(datastr):

try:

dt = json.loads(datastr)

except ValueError,e:

dt = {}

return dt

# Server-1 Process

def Server1_1():

serv1 = createUdpSock(s1_ip, s1_port1)

serv3 = createUdpSock(s1_ip, s1_port3)

while True:

datastr,addr = serv1.recvfrom(1024)

datadict = loadJsonStr(datastr)

datadict["cli_addr"] = addr[0]

datadict["cli_port"] = addr[1]

s1log = []

# notify Server2 Sendto

if s2_ip:

datadict["rStep"] = 4

nret = udpSendTo(serv1, s2_ip, s2_port1, datadict)

s1log.append('notify S2(%s) nsend=%d' % (s2_ip, nret))

datadict["rStep"] = 3

nret = udpSendTo(serv3, addr[0], addr[1], datadict) # other port response

s1log.append('s1_port3 resp nsend=%d' % nret)

datadict["rStep"] = 1

datadict["msglog"] = s1log

nret = udpSendTo(serv1, addr[0], addr[1], datadict) # response echo

s1log.append('s1_port1 resp nsend=%d' % nret)

print("Serv1-Recv| client="+str(addr)+'| detail=' + ';'.join(s1log))

# Server-1 Process

def Server1_2():

ServEcho(s1_ip, s1_port2, 2)

def ServEcho(servIP, servPort, rStep):

serv = createUdpSock(servIP, servPort)

while True:

datastr,addr = serv.recvfrom(1024)

datadict = loadJsonStr(datastr)

datadict["cli_addr"] = addr[0]

datadict["cli_port"] = addr[1]

datadict["rStep"] = rStep

udpSendTo(serv, addr[0], addr[1], datadict)

# Server-2 Process # listen for Server1's notify

def Server2_1():

serv1 = createUdpSock(s2_ip, s2_port1)

serv2 = createUdpSock(s2_ip, s2_port2)

while True:

datastr,addr = serv1.recvfrom(1024)

datadict = loadJsonStr(datastr)

if not "cli_addr" in datadict:

print('Invalid NotifyMsg:'+datastr)

continue

cliaddr = datadict["cli_addr"]

cliport = datadict["cli_port"]

# datadict["rStep"] = 4

nret = udpSendTo(serv2, cliaddr, cliport, datadict)

print('Serv1(%s) Notify test Client(%s), nsend=%d' % (addr,cliaddr, nret) )

# Server-2 Process # Check Last

def Server2_2():

ServEcho(s2_ip, s2_port3, 5)

# check is valid bind IP addr for server

def isValidServAddr(ipv4):

try:

addrs = socket.getaddrinfo(socket.gethostname(),None)

except:

addrs = []

addrlist = [item[4][0] for item in addrs if ':' not in item[4][0]]

bret = ipv4 in addrlist

if not bret:

try:

stmp = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

stmp.bind( (ipv4, 60330) )

bret = True

except BaseException,e:

bret = False

print('IpAddr %s isnot local addr%s'%(ipv4, addrlist))

print(e)

finally:

stmp.close()

return bret

def runS1():

if not isValidServAddr(s1_ip):

return 1

t1 = threading.Thread(target=Server1_1, name='S1-Listen1')

t2 = threading.Thread(target=Server1_2, name='S1-Echo')

t1.start()

t2.start()

t1.join()

t2.join()

return 0

def runS2():

if not isValidServAddr(s2_ip):

return 2

t1 = threading.Thread(target=Server2_1, name='S2-ListenNotify')

t2 = threading.Thread(target=Server2_2, name='S2-Echo')

t1.start()

t2.start()

t1.join()

t2.join()

return 0

# client process

def runClient():

clisock = createUdpSock(c_ip, c_port)

udpSendTo(clisock, s1_ip, s1_port1, {'step': 1})

udpSendTo(clisock, s1_ip, s1_port2, {'step': 2})

print('client Sock is %s' % str(clisock.getsockname()))

# 接收各路响应

resplst1 = udpRecvFrom(clisock, wait_timeout_ms, 4)

resplst2 = []

if s2_ip > '':

udpSendTo(clisock, s2_ip, s2_port3, {'step': 3}) # server-2 echo

resplst2 = udpRecvFrom(clisock, wait_timeout_ms, 1)

clisock.close()

calcSummery(resplst1, resplst2)

def calcSummery(rsp1, rsp2):

rspmap = {}

for item in rsp1+rsp2:

nitem = json.loads(item[0])

nitem['serv'] = item[1]

rspmap[nitem.get('rStep')] = nitem

print(nitem)

if not 1 in rspmap:

print('Server1 not work Or Offline')

return

if s2_ip > '' and not 5 in rspmap:

print('Server2 not work')

return

nat_type = 'unknow'

if s2_ip > '': # 完整的服务

if 4 in rspmap:

nat_type = 'NAT1 Cone'

elif rspmap[1]['cli_port'] != rspmap[5]['cli_port']:

nat_type = 'NAT4 Symmetric'

elif 3 in rspmap:

nat_type = 'NAT2 Address Restricted'

else:

nat_type = 'NAT3 Port Restricted'

else:

if rspmap[1]['cli_port'] != rspmap[2]['cli_port']:

nat_type = 'NAT4 Symmetric'

elif 3 in rspmap:

nat_type = 'NAT2 Address Restricted(Maybe) or NAT1'

else:

nat_type = 'NAT3 Port Restricted(Maybe)'

print("Test Summery: "+nat_type)

if __name__ == "__main__":

param = ''

if len(sys.argv) > 1:

param = sys.argv[1]

runfunlst = {'s1': runS1, 's2': runS2, 'c': runClient}

while not param in runfunlst:

param = raw_input('''Please Select Run Mode:

s1: Server-1 Process

s2: Server-2 Process

c: Client

>>''')

param = param.strip()

run = runfunlst[param]

run()