Python是一種高級編程語言，常常用于網絡編程。本文將介紹如何使用Python監聽數據包。

# 導入所需模塊
import socket
import struct
# 定義IP頭格式
ip_header = struct.Struct('!BBHHHBBH4s4s')
def parse_ip_header(data):
"""解析IP頭"""
version_header_length, tos, total_length, id_, flags_offset, ttl, protocol, checksum, source_address, dest_address = ip_header.unpack(data[:20])
version = version_header_length >>4
header_length = (version_header_length & 0xF) * 4
return version, header_length, ttl, protocol, source_address, dest_address, data[header_length:total_length]
# 定義TCP頭格式
tcp_header = struct.Struct('!HHLLBBHHH')
def parse_tcp_header(data):
"""解析TCP頭"""
source_port, dest_port, seq_num, ack_num, offset_reserved_flags, window_size, checksum, urgent_pointer = tcp_header.unpack(data[:20])
offset = (offset_reserved_flags >>4) * 4
flags = offset_reserved_flags & 0xF
return source_port, dest_port, seq_num, ack_num, flags, window_size, data[offset:]
# 創建套接字并監聽
HOST = '127.0.0.1'
PORT = 8888
with socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_TCP) as s:
s.bind((HOST, PORT))
s.setsockopt(socket.IPPROTO_IP, socket.IP_HDRINCL, 1)
s.ioctl(socket.SIO_RCVALL, socket.RCVALL_ON)
while True:
data, addr = s.recvfrom(65535)
version, header_length, ttl, protocol, source_address, dest_address, payload = parse_ip_header(data)
if protocol == socket.IPPROTO_TCP:
source_port, dest_port, seq_num, ack_num, flags, window_size, tcp_payload = parse_tcp_header(payload)
print(f'source_address: {source_address}, source_port: {source_port}, dest_address: {dest_address}, dest_port: {dest_port}, flags: {flags}, tcp_payload: {tcp_payload}')

以上代碼通過創建原始套接字，并監聽TCP數據包，解析IP頭和TCP頭，輸出相關信息。