CDN检测器：Python编程实现域名CDN使用情况的检测
在介绍这个用Python编写的CDN检测器工具之前，我们首先需要理解什么是CDN。CDN，全称内容分发网络（Content Distribution Network），是一种网络技术，它可以使用户更快地获取到所需内容。CDN通过将内容分布到全球各地的服务器上,用户在访问时可以直接从其网络位于最近的服务器上获得内容，大大提高了访问的速度和稳定性。
今天，我想向大家介绍的是一个由myfpga.cn的工程师ChanRa1n编写的用于检测域名是否使用了CDN的Python工具。这个工具使用一些Python的重要模块，如socket、ipaddress、requests等。
代码如下：
# -*- coding: utf-8 -*-
"""
Detect if a domain name is using CDN.
This module checks if the given URL is using a CDN by resolving the domain name's IP and comparing it with known CDN IP ranges.
It also includes a secondary check using the socket.getaddrinfo method.
Author: ChanRa1n
Email: chenyu@myfpga.cn
Creation Date: 2024/04/09
License: This software is intended for educational and learning purposes only. No warranty for software availability and security. Protect copyright and mitigate risks.
This software is provided "as is" without any guarantees or warranty. In association with the product, myfpga.cn makes no warranties of any kind, either express or implied, including but not limited to warranties of merchantability, fitness for a particular purpose, of title, or of noninfringement of third party rights. Use of the software by a user is at the user's risk.
Only for learning and educational purposes.
"""
import socket
import ipaddress
import os
import requests
def is_ip_in_cdn(ip, cdn_ranges):
ip_obj = ipaddress.ip_address(ip)
for cdn_range in cdn_ranges:
if ip_obj in ipaddress.ip_network(cdn_range, strict=False):
return True
return False
def read_cdn_ranges(filename='cdn_list.txt'):
# Check if the file exists in the current directory
if not os.path.exists(filename):
# If the file does not exist, try to fetch it from the web
try:
response = requests.get('https://myfpga.cn/library/Internet/cdn_list.txt')
response.raise_for_status() # Raises an HTTPError if the HTTP request returned an unsuccessful status code
# Split the content into lines
cdn_list_raw = response.text.splitlines()
except requests.HTTPError as err:
print(f"Failed to retrieve cdn_list.txt from the web: {err}")
return [] # Return an empty list on error
else:
with open(filename, 'r') as file:
cdn_list_raw = file.readlines()
# Filter comments and empty lines
return [line.strip() for line in cdn_list_raw if line.strip() and not line.startswith('#')]
def check_cdn_by_getaddrinfo(hostname):
try:
addr_info = socket.getaddrinfo(hostname, None)
return len(set([info[4][0] for info in addr_info])) > 1
except socket.error:
return False
def check_cdn(url, cdn_list_file='cdn_list.txt'):
hostname = url.split("//")[-1].split("/")[0]
cdn_ranges = read_cdn_ranges(cdn_list_file)
if not cdn_ranges: # If cdn_ranges is empty, either file read or web fetch failed
return False
try:
ip = socket.gethostbyname(hostname)
if is_ip_in_cdn(ip, cdn_ranges):
return True
else:
return check_cdn_by_getaddrinfo(hostname)
except socket.gaierror:
return False
def is_using_cdn(url):
return check_cdn(url)
# 测试代码
if __name__ == "__main__":
url_to_test = input("请输入URL：")
if is_using_cdn(url_to_test):
print("检测结果：是CDN或检测失败。")
else:
print("检测结果：不是CDN。")运行效果如图：
