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#
# This file is part of pysnmp software.
#
# Copyright (c) 2005-2019, Ilya Etingof <etingof@gmail.com>
# License: http://snmplabs.com/pysnmp/license.html
#
try:
import asyncio
except ImportError:
import trollius as asyncio
from pysnmp.hlapi.v1arch.auth import *
from pysnmp.hlapi.varbinds import *
from pysnmp.hlapi.v1arch.asyncio.transport import *
from pysnmp.smi.rfc1902 import *
from pysnmp.proto.api import v2c
from pysnmp.proto.proxy import rfc2576
__all__ = ['sendNotification']
VB_PROCESSOR = NotificationOriginatorVarBinds()
@asyncio.coroutine
def sendNotification(snmpDispatcher, authData, transportTarget,
notifyType, *varBinds, **options):
"""Creates a generator to send SNMP notification.
When iterator gets advanced by :py:mod:`asyncio` main loop,
SNMP TRAP or INFORM notification is send (:RFC:`1905#section-4.2.6`).
The iterator yields :py:class:`asyncio.Future` which gets done whenever
response arrives or error occurs.
Parameters
----------
snmpDispatcher: :py:class:`~pysnmp.hlapi.v1arch.asyncore.SnmpDispatcher`
Class instance representing asynio-based asynchronous event loop and
associated state information.
authData: :py:class:`~pysnmp.hlapi.v1arch.CommunityData`
Class instance representing SNMPv1/v2c credentials.
transportTarget: :py:class:`~pysnmp.hlapi.v1arch.asyncio.UdpTransportTarget` or
:py:class:`~pysnmp.hlapi.v1arch.asyncio.Udp6TransportTarget` Class instance representing
transport type along with SNMP peer address.
notifyType : str
Indicates type of notification to be sent. Recognized literal
values are *trap* or *inform*.
\*varBinds: :class:`tuple` of OID-value pairs or :py:class:`~pysnmp.smi.rfc1902.ObjectType` or :py:class:`~pysnmp.smi.rfc1902.NotificationType`
One or more objects representing MIB variables to place
into SNMP notification. It could be tuples of OID-values
or :py:class:`~pysnmp.smi.rfc1902.ObjectType` class instances
of :py:class:`~pysnmp.smi.rfc1902.NotificationType` objects.
Besides user variable-bindings, SNMP Notification PDU requires at
least two variable-bindings to be present:
0. SNMPv2-MIB::sysUpTime.0 = <agent uptime>
1. SNMPv2-SMI::snmpTrapOID.0 = <notification ID>
When sending SNMPv1 TRAP, more variable-bindings could be present:
2. SNMP-COMMUNITY-MIB::snmpTrapAddress.0 = <agent-IP>
3. SNMP-COMMUNITY-MIB::snmpTrapCommunity.0 = <snmp-community-name>
4. SNMP-COMMUNITY-MIB::snmpTrapEnterprise.0 = <enterprise-OID>
If user does not supply some or any of the above variable-bindings or
if they are at the wrong positions, the system will add/reorder the
missing ones automatically.
On top of that, some notification types imply including some additional
variable-bindings providing additional details on the event being
reported. Therefore it is generally easier to use
:py:class:`~pysnmp.smi.rfc1902.NotificationType` object which will
help adding relevant variable-bindings.
Other Parameters
----------------
\*\*options :
Request options:
* `lookupMib` - load MIB and resolve response MIB variables at
the cost of slightly reduced performance. Default is `False`,
unless :py:class:`~pysnmp.smi.rfc1902.ObjectType` or
:py:class:`~pysnmp.smi.rfc1902.NotificationType` is present
among `varBinds` in which case `lookupMib` gets automatically
enabled.
Yields
------
errorIndication: str
True value indicates SNMP engine error.
errorStatus: str
True value indicates SNMP PDU error.
errorIndex: int
Non-zero value refers to `varBinds[errorIndex-1]`
varBinds: tuple
A sequence of OID-value pairs in form of base SNMP types (if
`lookupMib` is `False`) or :py:class:`~pysnmp.smi.rfc1902.ObjectType`
class instances (if `lookupMib` is `True`) representing MIB variables
returned in SNMP response.
Raises
------
PySnmpError
Or its derivative indicating that an error occurred while
performing SNMP operation.
Examples
--------
>>> import asyncio
>>> from pysnmp.hlapi.asyncio import *
>>>
>>> @asyncio.coroutine
... def run():
... errorIndication, errorStatus, errorIndex, varBinds = yield from sendNotification(
... SnmpDispatcher(),
... CommunityData('public'),
... UdpTransportTarget(('demo.snmplabs.com', 162)),
... 'trap',
... NotificationType(ObjectIdentity('IF-MIB', 'linkDown')))
... print(errorIndication, errorStatus, errorIndex, varBinds)
...
>>> asyncio.get_event_loop().run_until_complete(run())
(None, 0, 0, [])
>>>
"""
sysUpTime = v2c.apiTrapPDU.sysUpTime
snmpTrapOID = v2c.apiTrapPDU.snmpTrapOID
def _ensureVarBinds(varBinds):
# Add sysUpTime if not present already
if not varBinds or varBinds[0][0] != sysUpTime:
varBinds.insert(0, (v2c.ObjectIdentifier(sysUpTime), v2c.TimeTicks(0)))
# Search for and reposition sysUpTime if it's elsewhere
for idx, varBind in enumerate(varBinds[1:]):
if varBind[0] == sysUpTime:
varBinds[0] = varBind
del varBinds[idx]
break
if len(varBinds) < 2:
raise error.PySnmpError('SNMP notification PDU requires '
'SNMPv2-MIB::snmpTrapOID.0 to be present')
# Search for and reposition snmpTrapOID if it's elsewhere
for idx, varBind in enumerate(varBinds[2:]):
if varBind[0] == snmpTrapOID:
del varBinds[idx]
if varBinds[1][0] == snmpTrapOID:
varBinds[1] = varBind
else:
varBinds.insert(1, varBind)
break
# Fail on missing snmpTrapOID
if varBinds[1][0] != snmpTrapOID:
raise error.PySnmpError('SNMP notification PDU requires '
'SNMPv2-MIB::snmpTrapOID.0 to be present')
return varBinds
def _cbFun(snmpDispatcher, stateHandle, errorIndication, rspPdu, _cbCtx):
if future.cancelled():
return
errorStatus = v2c.apiTrapPDU.getErrorStatus(rspPdu)
errorIndex = v2c.apiTrapPDU.getErrorIndex(rspPdu)
varBinds = v2c.apiTrapPDU.getVarBinds(rspPdu)
try:
varBindsUnmade = VB_PROCESSOR.unmakeVarBinds(snmpDispatcher.cache, varBinds,
lookupMib)
except Exception as e:
future.set_exception(e)
else:
future.set_result(
(errorIndication, errorStatus, errorIndex, varBindsUnmade)
)
lookupMib = options.get('lookupMib')
if not lookupMib and any(isinstance(x, (NotificationType, ObjectType))
for x in varBinds):
lookupMib = True
if lookupMib:
varBinds = VB_PROCESSOR.makeVarBinds(snmpDispatcher.cache, varBinds)
if notifyType == 'trap':
reqPdu = v2c.TrapPDU()
else:
reqPdu = v2c.InformRequestPDU()
v2c.apiTrapPDU.setDefaults(reqPdu)
v2c.apiTrapPDU.setVarBinds(reqPdu, varBinds)
varBinds = v2c.apiTrapPDU.getVarBinds(reqPdu)
v2c.apiTrapPDU.setVarBinds(reqPdu, _ensureVarBinds(varBinds))
if authData.mpModel == 0:
reqPdu = rfc2576.v2ToV1(reqPdu)
future = asyncio.Future()
snmpDispatcher.sendPdu(authData, transportTarget, reqPdu, cbFun=_cbFun)
if notifyType == 'trap':
def __trapFun(future):
if future.cancelled():
return
future.set_result((None, 0, 0, []))
loop = asyncio.get_event_loop()
loop.call_soon(__trapFun, future)
return future
|
