# -*- coding: utf8 -*-
"""@author: boyxuper@date: 2017/8/21 16:07"""import random
import socket
from collections import defaultdict
from itertools import chain
import clientsubnetoption
import dns
import dns.name
import dns.message
import dns.rdatatype
import dns.resolver
_logger = lambda *args: None
def logger_full(fmt, *args):
if not args:
print fmt
return
print fmt % args
socket.inet_pton = lambda _, p: socket.inet_aton(p)
socket.inet_ntop = lambda _, n: socket.inet_ntoa(n)
def retry(n=3, exc_list=()):
def decorator(fn):
def wrapper(*args, **kwargs):
tried = 1 while tried <= n:
try:
return fn(*args, **kwargs)
except exc_list as err:
print 'RETRY %s/%s, [%s]' % (tried, n, err)
tried += 1 else:
raise err
return wrapper
return decorator
@retry(n=5, exc_list=(dns.exception.Timeout, dns.resolver.NoAnswer, ))
def query_dns0(domain, ns_ip, client_ip=None, **kwargs):
kwargs.setdefault('rdtype', dns.rdatatype.A)
message = dns.message.make_query(domain, **kwargs)
if client_ip:
message.use_edns(options=[clientsubnetoption.ClientSubnetOption(client_ip)])
if callable(ns_ip):
ns_ip = ns_ip()
return dns.query.udp(message, ns_ip, timeout=TIMEOUT), ns_ip
# only authority can be cachedKNOWN_AUTHORITIES = defaultdict(list, **{
'.': ['192.5.5.241', '199.7.83.42', '192.58.128.30', '192.36.148.17'],
'net.': [
'192.48.79.30', '192.35.51.30', '192.52.178.30', '192.5.6.30',
'192.26.92.30', '192.41.162.30', '192.12.94.30', '192.54.112.30',
'192.31.80.30', '192.43.172.30', '192.33.14.30', '192.55.83.30', '192.42.93.30'],
'com.': ['192.33.14.30', '192.12.94.30', '192.55.83.30', '192.52.178.30',
'192.26.92.30', '192.48.79.30', '192.5.6.30', '192.43.172.30',
'192.42.93.30', '192.31.80.30', '192.54.112.30', '192.35.51.30', '192.41.162.30'],
'cn.': [
'203.119.29.1', '203.119.27.1', '203.119.28.1',
'203.119.26.1', '202.112.0.44', '203.119.25.1'],
})
NS_IPS = defaultdict(set)
TIMEOUT = 2
def locate_nearest_authority(dns_name):
""" :type dns_name: dns.name.Name """ for depth in range(len(dns_name), 0, -1):
_, sub = dns_name.split(depth)
if sub.to_text() in KNOWN_AUTHORITIES:
return sub, KNOWN_AUTHORITIES[sub.to_text()]
assert False, 'impossible'
def is_ip(s):
try:
socket.inet_aton(s)
except:
return False else:
return True
def _authority_iterator(authority_ips, client_ip, logger=_logger):
pos = random.randint(0, len(authority_ips))
# for short ips while True:
non_ips = []
for name in chain(authority_ips[pos:], authority_ips[:pos]):
if is_ip(name):
yield name
else:
non_ips.append(name)
for name in non_ips:
if name in NS_IPS:
server_ips = list(NS_IPS[name])
else:
_, server_ips, _ = resolve_A(name, client_ip=client_ip, logger=logger)
NS_IPS[name] = set(server_ips)
yield server_ips[pos % len(server_ips)]
@retry(n=5, exc_list=(dns.exception.Timeout, dns.resolver.NoAnswer, ))
def query_dns(dns_name, client_ip=None, logger=_logger, **kwargs):
sub, authority_ips = locate_nearest_authority(dns_name)
iterator = _authority_iterator(authority_ips, client_ip, logger=_logger)
logger('querying %s @NS"%s": %r', dns_name, sub, authority_ips)
response, ns_ip = query_dns0(dns_name, ns_ip=iterator.next, client_ip=client_ip, **kwargs)
resp_code = response.rcode()
if resp_code != dns.rcode.NOERROR:
if resp_code == dns.rcode.NXDOMAIN:
raise Exception('%s does not exist on %s.' % (sub, ns_ip))
else:
raise Exception('Error %s' % dns.rcode.to_text(resp_code))
return response
def resolve_A(domain, client_ip, logger=_logger):
""" :return: answers response.authority.__len__() == 1 response.authority.name == {Name}a.shifen.com. response.authority.items: 0 = {NS} ns2.a.shifen.com. 1 = {NS} ns3.a.shifen.com. 2 = {NS} ns4.a.shifen.com. 3 = {NS} ns1.a.shifen.com. 4 = {NS} ns5.a.shifen.com. """ if not domain.endswith('.'): domain += '.'
dns_name = dns.name.from_text(domain)
while True:
response = query_dns(dns_name, client_ip=client_ip, logger=logger)
# logger(response)
instant_ips = defaultdict(list)
final_answer = None
# authority contains NS should be processed last, so it can leverage the instant IPs for answer in chain(response.additional, response.answer, response.authority):
answer_name = answer.name.to_text()
for item in answer.items:
item_text = item.to_text()
if item.rdtype == dns.rdatatype.A:
if answer_name == domain: final_answer = answer
instant_ips[answer_name].append(item_text)
elif item.rdtype == dns.rdatatype.NS:
if domain not in instant_ips:
logger('got NS: %s -> %s', answer_name, item_text)
if item_text in instant_ips:
authority_ips = instant_ips[item_text]
NS_IPS[item_text].update(authority_ips)
else:
authority_ips = [item_text]
KNOWN_AUTHORITIES[answer_name].extend(authority_ips)
elif item.rdtype == dns.rdatatype.CNAME:
logger('CNAME: %s -> %s', domain, item_text)
domain, dns_name = item_text, dns.name.from_text(item_text)
if domain in instant_ips:
return domain, instant_ips[domain], final_answer.ttl
if __name__ == '__main__':
log = _logger
log = logger_full
print resolve_A('www.baidu.com', client_ip='8.8.8.8', logger=log)
print resolve_A('www.taobao.com', client_ip='8.8.8.8', logger=log)
print resolve_A('www.google.com', client_ip='8.8.8.8', logger=log)
print resolve_A('dl.tiku.zhan.com', client_ip='8.8.8.8', logger=log)
print resolve_A('ns3.dnsv4.com', client_ip='8.8.8.8', logger=log)
print resolve_A('www.facebook.com', client_ip='8.8.8.8', logger=log)
print resolve_A('api.taoqian123.com', client_ip='8.8.8.8', logger=log)
print resolve_A('hotsoon.snssdk.com', client_ip='66.103.188.117', logger=log)
