我们使用了原始套接字(socket.SOCK_RAW)来发送和接收ICMP消息,也就是通过模拟ICMP协议来进行UDP端口的探测。我们构造了一个简单的ICMP数据包,并将其发送到目标主机的特定端口。然后,我们等待接收目标主机返回的ICMP消息,并判断其类型和代码是否为端口不可达消息。如果是,则推断目标端口关闭;如果不是,则认为目标端口开放。
import socket
import os
import struct
import timedef udp_port_scan(target_ip, port):icmp = socket.getprotobyname("icmp")sock = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp)sock.settimeout(1) # 设置超时时间为1秒# 构造ICMP消息data = b'abcdefghijklmnopqrstuvwabcdefghi'icmp_packet = struct.pack("!BBHHH32s", 8, 0, 0, 0, 0, data)try:sock.sendto(icmp_packet, (target_ip, port))start_time = time.time()while True:try:recv_packet, addr = sock.recvfrom(1024)end_time = time.time()elapsed_time = (end_time - start_time) * 1000 # 计算往返时间icmp_header = recv_packet[20:28]icmp_type, code, checksum, packet_id, sequence = struct.unpack("!BBHHH", icmp_header)# 判断是否为ICMP端口不可达消息if type == 3 and code == 3 and packet_id == os.getpid() & 0xFFFF:print(f"Port {port} is closed")break# 此时可以认为端口开放print(f"Port {port} is open")breakexcept socket.timeout:print(f"Port {port} is closed")breakfinally:sock.close()target_ip = '192.168.0.1'
ports_to_scan = [80, 443, 22, 53] # 要探测的端口列表for port in ports_to_scan:udp_port_scan(target_ip, port)
请注意,在使用原始套接字和ICMP协议进行UDP端口探测时,可能需要使用管理员权限运行脚本。同时,由于涉及到底层协议和操作系统的原因,代码在不同的平台和环境中可能会有所调整。