def test_multiwalk_non_containment(self):
'''
Running a multiwalk should raise an exception if the agent returns OIDs
which are not properly increasing.
'''
from puresnmp.pdu import GetResponse
OID = ObjectIdentifier.from_string
# First case: Returned OIDs are the same
response = Sequence(
Integer(1), OctetString(b'public'),
GetResponse(123, [
VarBind(oid=OID('1.2.3'), value=Integer(30)),
VarBind(oid=OID('2.3.4'), value=Integer(40)),
]))
with patch('puresnmp.api.raw.Transport') as mck:
mck().send.side_effect = [to_bytes(response)]
mck().get_request_id.return_value = 0
with self.assertRaises(FaultySNMPImplementation):
list(multiwalk('::1', 'public', [
'1.2.3',
'2.3.4',
]))
# Second case: Returned OIDs are smaller
response = Sequence(
Integer(1), OctetString(b'public'),
GetResponse(123, [
VarBind(oid=OID('1.2.2'), value=Integer(30)),
VarBind(oid=OID('2.3.3'), value=Integer(40)),
]))
with patch('puresnmp.api.raw.Transport') as mck:
mck().send.side_effect = [to_bytes(response)]
mck().get_request_id.return_value = 0
with self.assertRaises(FaultySNMPImplementation):
list(multiwalk('::1', 'public', [
'1.2.3',
'2.3.4',
]))
def test_getnext_increasing_oid_strict(self):
'''
When running "getnext" we expect a different OID than the one we passed
in. If not, this can cause endless-loops in the worst case. Faulty SNMP
implementations may behave this way!
'''
requested_oid = ObjectIdentifier(1, 2, 3, 4)
response_object = Sequence(
Integer(1), OctetString(b'public'),
GetResponse(234, [VarBind(requested_oid, Integer(123))]))
response_bytes = to_bytes(response_object)
with patch('puresnmp.api.raw.send') as mck:
mck.return_value = response_bytes
with self.assertRaises(FaultySNMPImplementation):
getnext('::1', 'private', '1.2.3.4')
def test_walk_endless_loop(self):
'''
In rare cases, some devices fall into an endless loop by returning the
requested OID on a "getnext" call during a "walk" operation. A SNMP
client behaving according to the SNMP spec will fall into an endless
loop. This test fakes such a case and revents the loop.
'''
response_binds = [
VarBind(ObjectIdentifier(1, 2, 3), Integer(123)),
VarBind(ObjectIdentifier(1, 2, 4), Integer(124)),
VarBind(ObjectIdentifier(1, 2, 5), Integer(125)),
VarBind(ObjectIdentifier(1, 2, 5), Integer(125)), # same OID
VarBind(ObjectIdentifier(1, 2, 5), Integer(125)), # same OID
VarBind(ObjectIdentifier(1, 2, 5), Integer(125)), # same OID
]
response_packets = [
Sequence(Integer(1), OctetString(b'public'),
GetResponse(234, [bind])) for bind in response_binds
]
response_bytes = [to_bytes(packet) for packet in response_packets]
handler = CapturingHandler()
logger = getLogger('puresnmp')
logger.addHandler(handler)
with patch('puresnmp.api.raw.Transport') as mck:
mck().send.side_effect = response_bytes
mck().get_request_id.return_value = 0
result = list(walk('::1', 'private', '1.2', errors='warn'))
logger.removeHandler(handler)
# The last OID in the mocked responses is decreasing so we want to read
# just up to that point.
expected = [
VarBind(ObjectIdentifier(1, 2, 3), Integer(123)),
VarBind(ObjectIdentifier(1, 2, 4), Integer(124)),
VarBind(ObjectIdentifier(1, 2, 5), Integer(125)),
]
self.assertEqual(result, expected)
# We also want to make sure that we have a proper warning about this
handler.assertContains(WARNING, r'.*1.2.5.*')
def test_walk_increasing_oid_lenient(self):
'''
We want to be able to allow faulty SNMP implementations to at least try
to fetch the values in a walk which are not increasing. It should read
up to the values which are no longer increasing and emit a warning.
'''
logger = getLogger('puresnmp')
handler = CapturingHandler()
logger.addHandler(handler)
response_binds = [
VarBind(ObjectIdentifier(1, 2, 3), Integer(123)),
VarBind(ObjectIdentifier(1, 2, 4), Integer(124)),
VarBind(ObjectIdentifier(1, 2, 5), Integer(125)),
VarBind(ObjectIdentifier(1, 2, 1), Integer(121)), # non-increasing
]
response_packets = [
Sequence(Integer(1), OctetString(b'public'),
GetResponse(234, [bind])) for bind in response_binds
]
response_bytes = [to_bytes(packet) for packet in response_packets]
with patch('puresnmp.api.raw.Transport') as mck:
mck().send.side_effect = response_bytes
mck().get_request_id.return_value = 0
result = list(walk('::1', 'private', '1.2', errors='warn'))
# The last OID in the mocked responses is decreasing so we want to read
# just up to that point.
expected = [
VarBind(ObjectIdentifier(1, 2, 3), Integer(123)),
VarBind(ObjectIdentifier(1, 2, 4), Integer(124)),
VarBind(ObjectIdentifier(1, 2, 5), Integer(125)),
]
self.assertEqual(result, expected)
# We also want to make sure that we have a proper warning about this
handler.assertContains(WARNING, r'.*1.2.1.*1.2.5.*')
logger.removeHandler(handler)