Python中的数据包嗅探器

我想用Python3.5做一个包嗅探器,它捕获UDP、TCP和ICMP。这是一个简短的例子:

 import socket
 import struct

# the public network interface
HOST = socket.gethostbyname(socket.gethostname())
# create a raw socket and bind it to the public interface
s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_IP)

s.bind((HOST,0))

# Include IP headers
s.setsockopt(socket.IPPROTO_IP, socket.IP_HDRINCL, 1)

# receive all packages
s.ioctl(socket.SIO_RCVALL, socket.RCVALL_ON)

# receive a package
n=1
while(n<=400):
    print('Number ', n)
    data=s.recvfrom(65565)
    packet=data[0]
    address= data[1]
    header=struct.unpack('!BBHHHBBHBBBBBBBB', packet[:20])
    if(header[6]==6): #header[6] is the field of the Protocol
        print("Protocol = TCP")
    elif(header[6]==17):
        print("Protocol = UDP")
    elif(header[5]==1):
        print("Protocol = ICMP") 
    n=n+1

问题是它只捕获UDP数据包:( 输出:

Number  1 Protocol = UDP Number  2 Protocol = UDP Number  3 Protocol = UDP Number  4 Protocol = UDP Number  5 Protocol = UDP Number  6 Protocol = UDP Number  7

有两个选项:

• 嗅探器只能捕获UDP数据包。
• 我正在接收UDP数据包。

我认为最合理的答案是我的嗅探器不能正常工作,它只是捕获UDP。知道吗?