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Commit c1851723 authored by Taya Snijder's avatar Taya Snijder
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removed snmp library included in files

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1 merge request!26Resolve #2021 "04 16 branched from master snmp device"
from .v1 import SNMPv1
versions = {
1: SNMPv1,
}
def Manager(*args, version=1, **kwargs):
try:
cls = versions[version]
except KeyError as e:
msg = "'version' must be one of {}".format(list(versions.keys()))
raise ValueError(msg) from e
return cls(*args, **kwargs)
# used to indicate that a string cannot be decoded because it violates encoding rules
class EncodingError(Exception):
pass
# used to indicate that a response violates the protocol in some way
class ProtocolError(Exception):
pass
class Timeout(Exception):
pass
__all__ = ['RWLock']
from threading import Lock
# returns a pair of objects, (r, w), which constitute a
# writer-preferred reader/writer lock
def RWLock():
r = Lock()
w = Lock()
return RLock(r, w), WLock(r, w)
class ContextLock:
def __enter__(self):
self.acquire()
def __exit__(self, *args, **kwargs):
self.release()
class RLock(ContextLock):
def __init__(self, r, w):
self.r = r
self.w = w
self.mutex = Lock()
self.queue = Lock()
self.count = 0
def acquire(self):
with self.queue:
with self.r:
with self.mutex:
if not self.count:
self.w.acquire()
self.count += 1
def release(self):
with self.mutex:
self.count -= 1
if not self.count:
self.w.release()
class WLock(ContextLock):
def __init__(self, r, w):
self.r = r
self.w = w
self.mutex = Lock()
self.count = 0
def acquire(self):
with self.mutex:
if not self.count:
self.r.acquire()
self.count += 1
self.w.acquire()
def release(self):
self.w.release()
with self.mutex:
self.count -= 1
if not self.count:
self.r.release()
__all__ = [
'ASN1', 'INTEGER', 'OCTET_STRING', 'NULL', 'OID', 'SEQUENCE', 'UNSIGNED',
'Counter32', 'Gauge32', 'TimeTicks', 'Integer32', 'Counter64', 'IpAddress',
'VarBind', 'VarBindList', 'PDU', 'GetRequestPDU', 'GetNextRequestPDU',
'GetResponsePDU', 'SetRequestPDU', 'Message',
]
from copy import copy
import socket
from .exceptions import EncodingError, ProtocolError
def unpack(obj):
if len(obj) < 2:
raise EncodingError("object encoding is too short")
dtype = obj[0]
l = obj[1]
index = 2
if l & 0x80:
index += l & 0x7f
if len(obj) < index:
raise EncodingError("Long form length field is incomplete")
l = 0
for num in obj[2:index]:
l <<= 8
l += num
if len(obj) < index + l:
raise EncodingError("Invalid length field: object encoding too short")
return dtype, obj[index:index+l], obj[index+l:]
def length(l):
if l < 0x80:
return bytes([l])
bytearr = bytearray()
while l:
bytearr.append(l & 0xff)
l >>= 8
# this works as long as (l < 2^1008), which is super big
bytearr.append(len(bytearr) | 0x80)
return bytes(reversed(bytearr))
class ASN1:
def __init__(self, value=None, encoding=None):
self._encoding = encoding
self._value = value
def __repr__(self):
return "{}({})".format(self.__class__.__name__, self)
@classmethod
def copy(cls, obj):
return cls(encoding=obj.encoding)
@staticmethod
def deserialize(obj, cls=None, leftovers=False):
dtype, encoding, tail = unpack(obj)
if tail and not leftovers:
raise EncodingError("Unexpected trailing bytes")
if cls is None:
try:
cls = types[dtype]
except KeyError as e:
message = "Unknown type: '0x{:02x}'".format(dtype)
raise ProtocolError(message) from e
elif dtype != cls.TYPE:
message = "Expected type '0x{:02x}'; got '0x{:02x}'"
message = message.format(cls.TYPE, dtype)
raise ProtocolError(message)
obj = cls(encoding=encoding)
return (obj, tail) if leftovers else obj
def serialize(self):
return bytes([self.TYPE]) + length(len(self.encoding)) + self.encoding
# The following methods must be overwritten for sequence types
def __bool__(self):
return bool(self.value)
def __eq__(self, other):
return self.value == other
def __ge__(self, other):
return self.value >= other
def __gt__(self, other):
return self.value > other
def __le__(self, other):
return self.value <= other
def __lt__(self, other):
return self.value < other
def __ne__(self, other):
return self.value != other
def __str__(self):
return repr(self.value)
def poke(self):
self.value
### Primitive types ###
class INTEGER(ASN1):
SIGNED = True
@property
def encoding(self):
if self._encoding is None:
encoding = bytearray()
x = self._value
# do - while
while True:
encoding.append(x & 0xff)
x >>= 8
if x in (0, -1):
break
self._encoding = bytes(reversed(encoding))
return self._encoding
@property
def value(self):
if self._value is None:
negative = self.SIGNED and bool(self._encoding[0] & 0x80)
x = 0
for byte in self._encoding:
x <<= 8
x |= byte
if negative:
bits = 8 * len(self._encoding)
self._value = -(~x + (1 << bits) + 1)
else:
self._value = x
return self._value
class OCTET_STRING(ASN1):
@property
def encoding(self):
if self._encoding is None:
self._encoding = self._value
return self._encoding
@property
def value(self):
if self._value is None:
self._value = self._encoding
return self._value
class NULL(ASN1):
def __init__(self, value=None, encoding=None):
if encoding:
raise EncodingError("Non-null encoding for NULL type")
elif value is not None:
raise ValueError("NULL cannot have non-null value")
def __str__(self):
return ""
@property
def encoding(self):
return b''
@property
def value(self):
return None
class OID(ASN1):
@property
def encoding(self):
if self._encoding is None:
if self._value[0] == '.':
self._value = self.value[1:]
segments = [int(segment) for segment in self._value.split('.')]
if len(segments) > 1:
segments[1] += segments[0] * 40
segments = segments[1:]
encoding = bytearray()
for num in segments:
bytearr = bytearray()
while num > 0x7f:
bytearr.append(num & 0x7f)
num >>= 7
bytearr.append(num)
for i in range(1, len(bytearr)):
bytearr[i] |= 0x80
bytearr.reverse()
encoding += bytearr
self._encoding = bytes(encoding)
return self._encoding
@property
def value(self):
if self._value is None:
encoding = self._encoding
first = encoding[0]
oid = [str(num) for num in divmod(first, 40)]
val = 0
for byte in encoding[1:]:
val |= byte & 0x7f
if byte & 0x80:
val <<= 7
else:
oid.append(str(val))
val = 0
if val:
raise EncodingError("OID ended in a byte with bit 7 set")
self._value = '.'.join(oid)
return self._value
class SEQUENCE(ASN1):
EXPECTED = None
def __init__(self, *values, encoding=None):
self.expected = copy(self.EXPECTED)
self._encoding = encoding
self._values = values or None
def __bool__(self):
return bool(self.values)
def __eq__(self, other):
return self.values == other
def __ge__(self, other):
return self.values >= other
def __gt__(self, other):
return self.values > other
def __le__(self, other):
return self.values <= other
def __lt__(self, other):
return self.values < other
def __ne__(self, other):
return self.values != other
def __str__(self):
return repr(self)
def __repr__(self, depth=0):
string = "{}{}:\n".format('\t'*depth, self.__class__.__name__)
depth += 1
for entry in self.values:
if isinstance(entry, SEQUENCE):
string += entry.__repr__(depth=depth)
else:
string += "{}{}: {}\n".format(
'\t'*depth,
entry.__class__.__name__,
entry
)
return string
def poke(self):
for val in self.values:
val.poke()
@property
def encoding(self):
if self._encoding is None:
encodings = [None] * len(self.values)
for i in range(len(self.values)):
encodings[i] = self.values[i].serialize()
self._encoding = b''.join(encodings)
return self._encoding
@property
def values(self):
if self._values is None:
definite = isinstance(self.expected, list)
sequence = []
encoding = self._encoding
while encoding:
if definite:
try:
cls = self.expected[len(sequence)]
except IndexError as e:
message = "{} has too many elements"
message = message.format(self.__class__.__name__)
raise ProtocolError(message) from e
else:
cls = self.expected
obj, encoding = ASN1.deserialize(encoding, cls=cls, leftovers=True)
sequence.append(obj)
if definite and len(sequence) < len(self.expected):
message = "{} has too few elements"
message = message.format(self.__class__.__name__)
raise ProtocolError(message)
self._values = tuple(sequence)
return self._values
### Composed types ###
class UNSIGNED(INTEGER):
SIGNED = False
class Counter32(UNSIGNED):
pass
class Gauge32(UNSIGNED):
pass
class TimeTicks(UNSIGNED):
pass
class Integer32(INTEGER):
pass
class Counter64(UNSIGNED):
pass
class IpAddress(OCTET_STRING):
@property
def encoding(self):
if self._encoding is None:
self._encoding = socket.inet_aton(self._value)
return self._encoding
@property
def value(self):
if self._value is None:
if len(self._encoding) == 4:
self._value = socket.inet_ntoa(self._encoding)
else:
raise ProtocolError("IP Address must be 4 bytes long")
return self._value
class VarBind(SEQUENCE):
EXPECTED = [
OID,
None,
]
def __init__(self, *args, **kwargs):
super(VarBind, self).__init__(*args, **kwargs)
self.error = None
@property
def name(self):
return self.values[0]
@property
def value(self):
return self.values[1]
class VarBindList(SEQUENCE):
EXPECTED = VarBind
def __getitem__(self, index):
return self.values[index]
def __iter__(self):
return iter(self.values)
def __len__(self):
return len(self.values)
class PDU(SEQUENCE):
EXPECTED = [
INTEGER,
INTEGER,
INTEGER,
VarBindList,
]
def __init__(self, request_id=0, error_status=0, error_index=0, vars=None, encoding=None):
values = (
INTEGER.copy(UNSIGNED(request_id)),
INTEGER(error_status),
INTEGER(error_index),
vars,
) if encoding is None else ()
super(PDU, self).__init__(*values, encoding=encoding)
@property
def request_id(self):
return self.values[0]
@property
def error_status(self):
return self.values[1]
@property
def error_index(self):
return self.values[2]
@property
def vars(self):
return self.values[3]
class GetRequestPDU(PDU):
pass
class GetNextRequestPDU(PDU):
pass
class GetResponsePDU(PDU):
pass
class SetRequestPDU(PDU):
pass
class Message(SEQUENCE):
EXPECTED = [
INTEGER,
OCTET_STRING,
GetResponsePDU,
]
def __init__(self, version=0, community=b'public', data=None, encoding=None):
values = (
INTEGER(version),
OCTET_STRING(community),
data,
) if encoding is None else ()
super(Message, self).__init__(*values, encoding=encoding)
@property
def version(self):
return self.values[0]
@property
def community(self):
return self.values[1]
@property
def data(self):
return self.values[2]
types = {
0x02: INTEGER,
0x04: OCTET_STRING,
0x05: NULL,
0x06: OID,
0x30: SEQUENCE,
0x40: IpAddress,
0x41: Counter32,
0x42: Gauge32,
0x43: TimeTicks,
0x44: Integer32,
0x46: Counter64,
0xa0: GetRequestPDU,
0xa1: GetNextRequestPDU,
0xa2: GetResponsePDU,
0xa3: SetRequestPDU,
}
for dtype, cls in types.items():
cls.TYPE = dtype
This diff is collapsed.
class StatusError(Exception):
pass
class TooBig(StatusError):
pass
class NoSuchName(StatusError):
pass
class BadValue(StatusError):
pass
class ReadOnly(StatusError):
pass
class GenErr(StatusError):
pass
get:
create main event
get pend table for host or create one
get data table for host or create dummy
with pend table lock
for each oid in the request
if not refresh
if pending
continue
if found in cache
grab cached result
continue
add main event to the pend table
add oid to request
if there are oids to be sent
construct message
add message to requests table
send message
if an oid had an error
raise it now
if not waiting for response
return the values you do have
wait for all events
with data table read lock
for each oid
grab the value
- make sure it is present
- make sure there are no errors
return the values
listen thread:
check port number
decode message
pull request id
find the corresponding request
make sure it has the right number of varbinds
remove request from table
check error status
with data table write lock
get/create entry for host
for each varbind
give it the error found in the request error field
find the oid requested
make sure it matches the request
save varbind to data table
set the request event
monitor thread:
wait for next stale request, done, or 1 second (whichever comes first)
grab next request
if it is stale
if it has not timed out
resend it
else
set varbind error to timeout
signal event
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