基于Python原生asyncio模块对DNS正向和反向的解析

一、正向解析：域名解析IP地址

import asyncio
import socket

domains = [
    ('www.baidu.com', 'https'),
    ('cn.bing.com', 'https'),
    ('www.2345.com', 'https'),
]

async def main(loop, domains):
    domain_ip = {}
    for domain in domains:
        info = await loop.getaddrinfo(
            *domain,
            proto=socket.IPPROTO_TCP,
        )
        for host in info:
            if domain[0] in domain_ip:
                domain_ip[domain[0]].append(host[4][0])
            else:
                domain_ip[domain[0]] = [host[4][0]]
    return domain_ip

# 事件环循
event_loop = asyncio.get_event_loop()
try:
    get_future = asyncio.ensure_future(main(event_loop, domains))  # 相当于开启一个future
    event_loop.run_until_complete(get_future)
    print(get_future.result()) 
finally:
    event_loop.close()

输出的结果

{'www.baidu.com': ['14.215.177.39', '14.215.177.38'], 
'cn.bing.com': ['202.89.233.101', '202.89.233.100'], 
'www.2345.com': ['121.201.101.42']}

---

二、反向解析：IP地址解析域名

import asyncio

ip_ports = [
    ('66.33.211.242', 443),
]

async def main(loop, ip_ports):
    dns_dict = {}
    for ip_port in ip_ports:
        info = await loop.getnameinfo(ip_port)
        if ip_port in dns_dict:
            dns_dict[ip_port[0]].append(info)
        else:
            dns_dict[ip_port[0]] = info
    return dns_dict

event_loop = asyncio.get_event_loop()
try:
    get_future = asyncio.ensure_future(main(event_loop, ip_ports))  # 相当于开启一个future
    event_loop.run_until_complete(get_future)
    print(get_future.result())  
finally:
    event_loop.close()

输出结果

{'66.33.211.242': ('apache2-zoo.george-washington.dreamhost.com', 'https')}