我是Python的初学者，如果我使用Python 3而不是Python 2执行该程序，则会在程序中发现以下奇怪行为。
我将尝试详细解释这种情况。
我在计算机上安装了这两个版本的Python：
然后我使用Scapy使用此脚本：
#!usr/bin/env python
# INSTALL THE FOLLOWING PYTHON MODULES:
# - pip3 install scapy
# - pip3 install scapy_http
import scapy.all as scapy
from scapy.layers import http
#
def sniff(interface):
# iface: specify the interface used to sniff on.
# store: I tell scapy to not store packets in memory.
# prn: allows to specify a callback function (a function that is call every time that the sniff() function sniff
# a packet.
# OPTIONAL FILTERS: uses to specifies filters packets using "BPF syntax"
# SOME FILTER EXAMPLES:
# - udp: filter UDP packets
# - arp: filter ARP packets
# - tcp: filter TCP packets
# - port 21: filter packets on a specific port
# DOCUMENTATION LINK: https://scapy.readthedocs.io/en/latest/extending.html
#scapy.sniff(iface=interface, store=False, prn=process_sniffed_packet, filter=80)
scapy.sniff(iface=interface, store=False, prn=process_sniffed_packet)
def process_sniffed_packet(packet):
#print(packet)
# Check if our packet has HTTP layer. If our packet has the HTTP layer and it is HTTPRequest.
# In this way I am excluding some garbage information in which I am not interested into.
if packet.haslayer(http.HTTPRequest):
print(packet)
print("-------------------------------------")
#print(packet.decode("utf-8"))
print(type(packet))
sniff("eth0")
此脚本通过HTTP协议实现了简单的流量嗅探器。
[[Python 2使用的scapy的版本应该是这个：
root@kali:~/Documents/PycharmWS/packet_sniffer# pip show scapy
Name: scapy
Version: 2.4.3
Summary: Scapy: interactive packet manipulation tool
Home-page: https://scapy.net
Author: Philippe BIONDI
Author-email: phil(at)secdev.org
License: GPLv2
Location: /usr/lib/python2.7/dist-packages
Requires:
Required-by:
[Python 3使用的
scapy的版本应该是这个：
root@kali:~/Documents/PycharmWS/packet_sniffer# pip3 show scapy
Name: scapy
Version: 2.4.3
Summary: Scapy: interactive packet manipulation tool
Home-page: https://scapy.net
Author: Philippe BIONDI
Author-email: phil(at)secdev.org
License: GPLv2
Location: /usr/lib/python3/dist-packages
Requires:
Required-by:
所以基本上版本是相同的：2.4.3，并且应该以相同的方式工作（基于Python版本，它只是从不同的目录中获取的。）>
此功能打印包内容时发生奇怪的行为：
def process_sniffed_packet(packet):
#print(packet)
# Check if our packet has HTTP layer. If our packet has the HTTP layer and it is HTTPRequest.
# In this way I am excluding some garbage information in which I am not interested into.
if packet.haslayer(http.HTTPRequest):
print(packet)
print("-------------------------------------")
#print(packet.decode("utf-8"))
print(type(packet))
这里发生了一件奇怪的事情：
使用使用Python 2.7.17]执行脚本，我获得了预期的输出：
root@kali:~/Documents/PycharmWS/packet_sniffer# python packet_sniffer.py jA">�P▒���NPOST / HTTP/1.1� Host: ocsp.int-x3.letsencrypt.org User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0 Accept: */* Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate Content-Type: application/ocsp-request Content-Length: 85 Connection: keep-alive 0S0Q0O0M0K0 +▒~�j�r����� dl�-`]�Jjc}ݺ��9��Ee�������� *y��8:�3zyJ�
Python 3.7.7]解释脚本时，我得到了这个奇怪的编码输出：
root@kali:~/Documents/PycharmWS/packet_sniffer# python3 packet_sniffer.py b'\x00PV\xfd\xa9B\x00PV)\x97\xc7\x08\x00E\x00\x01\xa7\xe8R@\x00@\x06\x9fI\xc0\xa8\xdf\x85\x97\x1dzi\xbaL\x00P\xc3\rj\x11A">\xd1P\x18\xfa\xf0\xb3N\x00\x00POST / HTTP/1.1\r\nHost: ocsp.int-x3.letsencrypt.org\r\nUser-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0\r\nAccept: */*\r\nAccept-Language: en-US,en;q=0.5\r\nAccept-Encoding: gzip, deflate\r\nContent-Type: application/ocsp-request\r\nContent-Length: 85\r\nConnection: keep-alive\r\n\r\n0S0Q0O0M0K0\t\x06\x05+\x0e\x03\x02\x1a\x05\x00\x04\x14~\xe6j\xe7r\x9a\xb3\xfc\xf8\xa2 dl\x16\xa1-`q\x08]\x04\x14\xa8Jjc\x04}\xdd\xba\xe6\xd19\xb7\xa6Ee\xef\xf3\xa8\xec\xa1\x02\x12\x03\x16\xe6\x87\xfc *y\xc1\xe48:\xdf3zyJ\xa4'
注：最初我怀疑这是字节数组的输出（因为它以** b开头），但不是，我使用：打印了
packet
变量的类型。print(type(packet))
并且对象类型是：<class 'scapy.layers.l2.Ether'>
所以我怀疑这个
scapy.layers.l2.Ether包含一个对象，该对象以这种方式或类似方式打印。无论如何，这应该是pip安装它的文件夹检索到的scapy.layers.l2.Ether代码：bytearray
class Ether(Packet):
name = "Ethernet"
fields_desc = [DestMACField("dst"),
SourceMACField("src"),
XShortEnumField("type", 0x9000, ETHER_TYPES)]
__slots__ = ["_defrag_pos"]
def hashret(self):
return struct.pack("H", self.type) + self.payload.hashret()
def answers(self, other):
if isinstance(other, Ether):
if self.type == other.type:
return self.payload.answers(other.payload)
return 0
def mysummary(self):
return self.sprintf("%src% > %dst% (%type%)")
@classmethod
def dispatch_hook(cls, _pkt=None, *args, **kargs):
if _pkt and len(_pkt) >= 14:
if struct.unpack("!H", _pkt[12:14])[0] <= 1500:
return Dot3
return cls
Python 2]打印此对象时，我获得了预期的输出，但使用了Python 3
打印了该对象，却得到了这个奇怪的“加密”输出？我想念什么？有没有一种方法可以使用Python 3正确打印此输出？我知道我可以使用：
packet.show()
代替print(packet)
但是我必须使用此
print（packet），因为我正在学习使用此特定输出来解析它的教程
我是使用Python的绝对初学者，如果我使用Python 3而不是Python 2执行它，我会在程序中发现以下奇怪的行为。我将尝试解释这种情况……
< [print(bytes(packet).decode(errors="backslashreplace"))