Files
dnsverify/dnsverify.py
2021-08-18 01:08:41 +02:00

117 lines
3.7 KiB
Python

#!/usr/bin/env python
# author: Philipp Gassmann <gassmann@puzzle.ch>
# check if domains configured with octodns are configured to use our nameservers
# Usage: ./dnsverify.py 2> /dev/null
import sys
import yaml
from pprint import pprint
import dns.query
import dns.resolver
from dns.exception import DNSException
def puzzle_nameservers():
dnspool = [
"ns1.dnsimple.com.",
"ns2.dnsimple.com.",
"ns3.dnsimple.com.",
"ns4.dnsimple.com.",
"ns5.dnsmadeeasy.com.",
"ns6.dnsmadeeasy.com.",
"ns7.dnsmadeeasy.com." ]
return dnspool
# query_authoritative_ns() based on https://stackoverflow.com/questions/4066614/how-can-i-find-the-authoritative-dns-server-for-a-domain-using-dnspython
def query_authoritative_ns(domain, log=lambda msg: None):
#default_resolver = dns.resolver.get_default_resolver()
my_resolver = dns.resolver.Resolver()
my_resolver.nameservers = ['8.8.8.8']
nameserver = my_resolver.nameservers[0]
n = domain.split('.')
for i in range(len(n), 0, -1):
sub = '.'.join(n[i-1:])
log('Looking up %s on %s' % (sub, nameserver))
query = dns.message.make_query(sub, dns.rdatatype.NS)
response = dns.query.tcp(query, nameserver)
rcode = response.rcode()
if rcode != dns.rcode.NOERROR:
if rcode == dns.rcode.NXDOMAIN:
raise Exception('%s does not exist.' % (sub))
else:
raise Exception('Error %s' % (dns.rcode.to_text(rcode)))
if len(response.authority) > 0:
rrsets = response.authority
elif len(response.additional) > 0:
rrsets = [response.additional]
else:
rrsets = response.answer
# Handle all RRsets, not just the first one
for rrset in rrsets:
for rr in rrset:
if rr.rdtype == dns.rdatatype.SOA:
log('Same server is authoritative for %s' % (sub))
elif rr.rdtype == dns.rdatatype.A:
ns = rr.items[0].address
log('Glue record for %s: %s' % (rr.name, ns))
elif rr.rdtype == dns.rdatatype.NS:
authority = rr.target
nameserver = my_resolver.query(authority).rrset[0].to_text()
log('%s [%s] is authoritative for %s; ttl %i' %
(authority, nameserver, sub, rrset.ttl))
result = rrset
else:
# IPv6 glue records etc
#log('Ignoring %s' % (rr))
pass
return result
def log (msg):
sys.stderr.write(msg + u'\n')
def domains_from_config(filename):
filecontent = open(filename, 'r')
config_domains = yaml.load(filecontent, Loader=yaml.FullLoader)
domains = config_domains['zones'].keys()
return domains
def verify_whois(domain):
domain = domain.strip('.')
result = query_authoritative_ns(domain, log)
for entry in result:
nameserver = entry.target.to_text()
if not nameserver in puzzle_nameservers():
print('Domain %s has authoritative NS %s which is not in puzzle_nameservers' % (domain, nameserver))
return False
log('Domain %s is ok' % (domain))
return True
def verify_domains_from_config(filename):
status_success = True
domains = domains_from_config(filename)
for domain in domains:
if not verify_whois(domain):
status_success = False
return status_success
if __name__ == "__main__":
global_status_success = True
for domain in [
'./puzzle.ch.yaml',
'./puzzle.yaml',
'./nonpuzzle.yaml'
]:
if not verify_domains_from_config(domain):
global_status_success = False
if not global_status_success:
exit(1)