#!/usr/bin/python3 # # Tests the DNS configuration of a Mail-in-a-Box. # # tests/dns.py ipaddr hostname # # where ipaddr is the IP address of your Mail-in-a-Box # and hostname is the domain name to check the DNS for. import sys, subprocess, re, difflib if len(sys.argv) < 3: print("Usage: tests/dns.py ipaddress hostname") sys.exit(1) ipaddr, hostname = sys.argv[1:] # construct the expected output subs = { "ipaddr": ipaddr, "hostname": hostname } expected = """ {hostname}. ##### IN A {ipaddr} {hostname}. ##### IN NS ns1.{hostname}. {hostname}. ##### IN NS ns2.{hostname}. ns1.{hostname}. ##### IN A {ipaddr} ns2.{hostname}. ##### IN A {ipaddr} www.{hostname}. ##### IN A {ipaddr} {hostname}. ##### IN MX 10 {hostname}. {hostname}. ##### IN TXT "v=spf1 mx -all" mail._domainkey.{hostname}. ##### IN TXT "v=DKIM1\; k=rsa\; s=email\; " "p=__KEY__" """.format(**subs).strip() + "\n" def dig(server, digargs): # run dig and clean the output response = subprocess.check_output(['dig', '@' + server, "+noadditional", "+noauthority"] + digargs).decode('utf8') response = re.sub('[\r\n]+', '\n', response) # remove blank lines response = re.sub('\n;.*', '', response) # remove comments response = re.sub('(\n\S+\s+)(\d+)', r'\1#####', response) # normalize TTLs response = re.sub(r"(\"p=).*(\")", r"\1__KEY__\2", response) # normalize DKIM key response = response.strip() + "\n" return response def test(server, description): digoutput = \ dig(server, [hostname])\ + dig(server, ["ns", hostname]) \ + dig(server, ["ns1." + hostname]) \ + dig(server, ["ns2." + hostname]) \ + dig(server, ["www." + hostname]) \ + dig(server, ["mx", hostname]) \ + dig(server, ["txt", hostname]) \ + dig(server, ["txt", "mail._domainkey." + hostname]) return test2(digoutput, server, description, expected) def test_ptr(server, description): ipaddr_reversed = ".".join( reversed( ipaddr.split(".") ) ) expected = "%s.in-addr.arpa. ##### IN PTR %s.\n" % (ipaddr_reversed, hostname) digoutput = dig(server, ["-x", ipaddr]) return test2(digoutput, server, description, expected) def test2(digoutput, server, description, expected): # Show a diff if there are any changes has_diff = False def split(s): return [line+"\n" for line in s.split("\n")] for line in difflib.unified_diff(split(expected), split(digoutput), fromfile='expected DNS settings', tofile=description): if not has_diff: print("The response from %s (%s) is not correct:" % (description, server)) print() has_diff = True sys.stdout.write(line) return not has_diff # Test the response from the machine itself. if not test(ipaddr, "Mail-in-a-Box"): print () print ("Please run the Mail-in-a-Box setup script on %s again." % hostname) sys.exit(1) else: # If those settings are OK, also test Google's Public DNS # to see if the machine is hooked up to recursive DNS properly. if not test("8.8.8.8", "Google Public DNS"): print () print ("Check that the nameserver settings for %s are correct at your domain registrar. It may take a few hours for Google Public DNS to update after changes on your Mail-in-a-Box." % hostname) sys.exit(1) else: # And if that's OK, also check reverse DNS (the PTR record). if not test_ptr("8.8.8.8", "Google Public DNS (Reverse DNS)"): print () print ("The reverse DNS for %s is not correct. Consult your ISP for how to set the reverse DNS (also called the PTR record) for %s to %s." % (hostname, hostname, ipaddr)) sys.exit(1) else: print ("DNS is OK.")