def test_followCanonicalName(self):
"""
If no record of the requested type is included in a response, but a
I{CNAME} record for the query name is included, queries are made to
resolve the value of the I{CNAME}.
"""
servers = {
("1.1.2.3", 53): {
(b"example.com", A): {
"answers":
[(b"example.com", Record_CNAME(b"example.net"))],
},
(b"example.net", A): {
"answers": [(b"example.net", Record_A("10.0.0.5"))],
},
},
}
resolver = self._getResolver(servers)
d = resolver.lookupAddress(b"example.com")
d.addCallback(lambda results: results[0]) # Get the answer section
d.addCallback(
self.assertEqual,
[
RRHeader(b"example.com",
CNAME,
payload=Record_CNAME(b"example.net")),
RRHeader(b"example.net", A, payload=Record_A("10.0.0.5")),
],
)
return d
def test_returnCanonicalName(self):
"""
If a I{CNAME} record is encountered as the answer to a query for
another record type, that record is returned as the answer.
"""
servers = {
("1.1.2.3", 53): {
(b"example.com", A): {
"answers": [
(b"example.com", Record_CNAME(b"example.net")),
(b"example.net", Record_A("10.0.0.7")),
],
},
},
}
resolver = self._getResolver(servers)
d = resolver.lookupAddress(b"example.com")
d.addCallback(lambda results: results[0]) # Get the answer section
d.addCallback(
self.assertEqual,
[
RRHeader(b"example.com",
CNAME,
payload=Record_CNAME(b"example.net")),
RRHeader(b"example.net", A, payload=Record_A("10.0.0.7")),
],
)
return d
def test_followCanonicalName(self):
"""
If no record of the requested type is included in a response, but a
I{CNAME} record for the query name is included, queries are made to
resolve the value of the I{CNAME}.
"""
servers = {
('1.1.2.3', 53): {
('example.com', A): {
'answers': [('example.com', Record_CNAME('example.net'))],
},
('example.net', A): {
'answers': [('example.net', Record_A('10.0.0.5'))],
},
},
}
resolver = self._getResolver(servers)
d = resolver.lookupAddress('example.com')
d.addCallback(lambda (ans, auth, add): ans)
d.addCallback(self.assertEquals, [
RRHeader('example.com', CNAME,
payload=Record_CNAME('example.net')),
RRHeader('example.net', A, payload=Record_A('10.0.0.5'))
])
return d
def test_detectCanonicalNameLoop(self):
"""
If there is a cycle between I{CNAME} records in a response, this is
detected and the L{Deferred} returned by the lookup method fails
with L{ResolverError}.
"""
servers = {
('1.1.2.3', 53): {
('example.com', A): {
'answers': [('example.com', Record_CNAME('example.net')),
('example.net', Record_CNAME('example.com'))],
},
},
}
resolver = self._getResolver(servers)
d = resolver.lookupAddress('example.com')
return self.assertFailure(d, ResolverError)
def test_returnCanonicalName(self):
"""
If a I{CNAME} record is encountered as the answer to a query for
another record type, that record is returned as the answer.
"""
servers = {
('1.1.2.3', 53): {
('example.com', A): {
'answers': [('example.com', Record_CNAME('example.net')),
('example.net', Record_A('10.0.0.7'))],
},
},
}
resolver = self._getResolver(servers)
d = resolver.lookupAddress('example.com')
d.addCallback(lambda (ans, auth, add): ans)
d.addCallback(self.assertEquals, [
RRHeader('example.com', CNAME,
payload=Record_CNAME('example.net')),
RRHeader('example.net', A, payload=Record_A('10.0.0.7'))
])
return d
