From: Michael Tremer <michael.tremer@ipfire.org>
Date: Thu, 8 Jan 2026 10:27:51 +0000 (+0000)
Subject: checker: Accept empty responses
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bb5b6e33b731501d45dea293505f7d42a61d5ce7;p=dbl.git

checker: Accept empty responses

When we are querying for something.example.org, we will get the SOA of
example.org. dnspython still considers this a NoAnswer, but actually
this is good enough to tell us that the domain is alive.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/dnsbl/checker.py b/src/dnsbl/checker.py
index 7c76026..8bb8df2 100644
--- a/src/dnsbl/checker.py
+++ b/src/dnsbl/checker.py
@@ -174,8 +174,8 @@ class Checker(object):
 		except dns.resolver.NoAnswer as e:
 			response = e.response()
 
-			# If we have received a CNAME, we will resolve again
 			if response:
+				# If we have received a CNAME, we will resolve again
 				for rrset in response.answer:
 					if rrset.rdtype == dns.rdatatype.CNAME:
 						for record in rrset:
@@ -183,8 +183,9 @@ class Checker(object):
 
 							return self.submit(domain, hostname=hostname)
 
-			# If there has been no response, we assume that the domain does not exist
-			status = False
+			# If we have received no response, that does mean that we might not
+			# have found the root of the domain, but something at least responded.
+			status = True
 
 		# NXDOMAIN
 		except dns.resolver.NXDOMAIN as e: