Merge pull request #2576 from Spitfireap/dnsblprovider

Mitigate spamhaus dns fail while querying for dnsbl

modoboa/admin/management/commands/subcommands/_mx.py

@@ -79,6 +79,11 @@ class CheckMXRecords(BaseCommand):
             pattern = "{}.{}.".format(reverse, provider)
             try:
                 result = socket.gethostbyname(pattern)
+                #result from dnsbl is in ipv4 format
+                splited_result = result.split(".")
+                if int(splited_result[-1]) > 15:
+                    #Typical dnsbl result : 127.0.0.[1-15] (depends on services)
+                    result = False
             except socket.gaierror:
                 result = False
             for mx in mxs:

modoboa/admin/tests/test_mx.py

@@ -217,10 +217,23 @@ class DNSBLTestCase(ModoTestCase):
         """Check notifications."""
         mock_query.side_effect = utils.mock_dns_query_result
         mock_getaddrinfo.side_effect = utils.mock_ip_query_result
-        mock_g_gethostbyname.return_value = "1.2.3.4"
+        mock_g_gethostbyname.return_value = "127.0.0.4"
         management.call_command(
             "modo", "check_mx", "--email", "user@example.test")
         self.assertEqual(len(mail.outbox), 2)
+    
+    @mock.patch("gevent.socket.gethostbyname")
+    @mock.patch("socket.getaddrinfo")
+    @mock.patch.object(dns.resolver.Resolver, "resolve")
+    def test_notifications_wrong_dnsbl_response(
+            self, mock_query, mock_getaddrinfo, mock_g_gethostbyname):
+        """Check notifications."""
+        mock_query.side_effect = utils.mock_dns_query_result
+        mock_getaddrinfo.side_effect = utils.mock_ip_query_result
+        mock_g_gethostbyname.return_value = "127.255.255.254" #<--Spamhaus response when querying from an open resolver
+        management.call_command(
+            "modo", "check_mx", "--email", "user@example.test")
+        self.assertEqual(len(mail.outbox), 1)
 
     @mock.patch("gevent.socket.gethostbyname")
     @mock.patch("socket.getaddrinfo")