diff --git a/management/dns_update.py b/management/dns_update.py index 9256c0ff..ead03a55 100755 --- a/management/dns_update.py +++ b/management/dns_update.py @@ -1030,17 +1030,29 @@ def set_secondary_dns(hostnames, env): resolver = dns.resolver.get_default_resolver() resolver.timeout = 5 resolver.lifetime = 5 - + for item in hostnames: if not item.startswith("xfr:"): # Resolve hostname. - try: - response = resolver.resolve(item, "A") - except (dns.resolver.NoNameservers, dns.resolver.NXDOMAIN, dns.resolver.NoAnswer, dns.resolver.Timeout): + tries = 2 + + while tries > 0: + tries = tries - 1 try: - response = resolver.resolve(item, "AAAA") - except (dns.resolver.NoNameservers, dns.resolver.NXDOMAIN, dns.resolver.NoAnswer, dns.resolver.Timeout): - raise ValueError("Could not resolve the IP address of %s." % item) + response = resolver.resolve(item, "A") + tries = 0 + except (dns.resolver.NoNameservers, dns.resolver.NXDOMAIN, dns.resolver.NoAnswer): + try: + response = resolver.resolve(item, "AAAA") + tries = 0 + except (dns.resolver.NoNameservers, dns.resolver.NXDOMAIN, dns.resolver.NoAnswer): + raise ValueError("Could not resolve the IP address of %s." % item) + except (dns.resolver.Timeout): + if tries < 1: + raise ValueError("Could not resolve the IP address of %s due to timeout." % item) + except (dns.resolver.Timeout): + if tries < 1: + raise ValueError("Could not resolve the IP address of %s due to timeout." % item) else: # Validate IP address. try: diff --git a/management/status_checks.py b/management/status_checks.py index 675b8f74..29ce2dc1 100755 --- a/management/status_checks.py +++ b/management/status_checks.py @@ -303,7 +303,7 @@ def run_network_checks(env, output): # by a spammer, or the user may be deploying on a residential network. We # will not be able to reliably send mail in these cases. rev_ip4 = ".".join(reversed(env['PUBLIC_IP'].split('.'))) - zen = query_dns(rev_ip4+'.zen.spamhaus.org', 'A', nxdomain=None) + zen = query_dns(rev_ip4+'.zen.spamhaus.org', 'A', nxdomain=None, retry = False) if zen is None: output.print_ok("IP address is not blacklisted by zen.spamhaus.org.") elif zen == "[timeout]": @@ -739,7 +739,7 @@ def check_mail_domain(domain, env, output): # Stop if the domain is listed in the Spamhaus Domain Block List. # The user might have chosen a domain that was previously in use by a spammer # and will not be able to reliably send mail. - dbl = query_dns(domain+'.dbl.spamhaus.org', "A", nxdomain=None) + dbl = query_dns(domain+'.dbl.spamhaus.org', "A", nxdomain=None, retry=False) if dbl is None: output.print_ok("Domain is not blacklisted by dbl.spamhaus.org.") elif dbl == "[timeout]": @@ -775,7 +775,7 @@ def check_web_domain(domain, rounded_time, ssl_certificates, env, output): # website for also needs a signed certificate. check_ssl_cert(domain, rounded_time, ssl_certificates, env, output) -def query_dns(qname, rtype, nxdomain='[Not Set]', at=None, as_list=False): +def query_dns(qname, rtype, nxdomain='[Not Set]', at=None, as_list=False, retry=True): # Make the qname absolute by appending a period. Without this, dns.resolver.query # will fall back a failed lookup to a second query with this machine's hostname # appended. This has been causing some false-positive Spamhaus reports. The @@ -800,15 +800,25 @@ def query_dns(qname, rtype, nxdomain='[Not Set]', at=None, as_list=False): # lifetime expires a dns.exception.Timeout exception will be raised. resolver.lifetime = 5 + if retry: + tries = 2 + else: + tries = 1 + # Do the query. - try: - response = resolver.resolve(qname, rtype) - except (dns.resolver.NoNameservers, dns.resolver.NXDOMAIN, dns.resolver.NoAnswer): - # Host did not have an answer for this query; not sure what the - # difference is between the two exceptions. - return nxdomain - except dns.exception.Timeout: - return "[timeout]" + while tries > 0: + tries = tries - 1 + try: + response = resolver.resolve(qname, rtype, search=True) + tries = 0 + except (dns.resolver.NoNameservers, dns.resolver.NXDOMAIN, dns.resolver.NoAnswer): + # Host did not have an answer for this query; not sure what the + # difference is between the two exceptions. + if tries < 1: + return nxdomain + except dns.exception.Timeout: + if tries < 1: + return "[timeout]" # Normalize IP addresses. IP address --- especially IPv6 addresses --- can # be expressed in equivalent string forms. Canonicalize the form before