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#
# This file is part of pysnmp software.
#
# Copyright (c) 2005-2018, Ilya Etingof <etingof@gmail.com>
# License: http://snmplabs.com/pysnmp/license.html
#
import sys
from pysnmp.proto import rfc1902, rfc1905, rfc3411, errind, error
from pysnmp.proto.api import v2c # backend is always SMIv2 compliant
from pysnmp.proto.proxy import rfc2576
import pysnmp.smi.error
from pysnmp import debug
# 3.2
class CommandResponderBase(object):
acmID = 3 # default MIB access control method to use
pduTypes = ()
def __init__(self, snmpEngine, snmpContext):
snmpEngine.msgAndPduDsp.registerContextEngineId(
snmpContext.contextEngineId, self.pduTypes, self.processPdu
)
self.snmpContext = snmpContext
self.__pendingReqs = {}
def handleMgmtOperation(self, snmpEngine, stateReference, contextName,
PDU, acInfo):
pass
def close(self, snmpEngine):
snmpEngine.msgAndPduDsp.unregisterContextEngineId(
self.snmpContext.contextEngineId, self.pduTypes
)
self.snmpContext = self.__pendingReqs = None
def sendVarBinds(self, snmpEngine, stateReference,
errorStatus, errorIndex, varBinds):
(messageProcessingModel, securityModel, securityName,
securityLevel, contextEngineId, contextName,
pduVersion, PDU, origPdu, maxSizeResponseScopedPDU,
statusInformation) = self.__pendingReqs[stateReference]
v2c.apiPDU.setErrorStatus(PDU, errorStatus)
v2c.apiPDU.setErrorIndex(PDU, errorIndex)
v2c.apiPDU.setVarBinds(PDU, varBinds)
debug.logger & debug.flagApp and debug.logger(
'sendVarBinds: stateReference %s, errorStatus %s, errorIndex %s, varBinds %s' % (
stateReference, errorStatus, errorIndex, varBinds)
)
self.sendPdu(snmpEngine, stateReference, PDU)
def sendPdu(self, snmpEngine, stateReference, PDU):
(messageProcessingModel, securityModel, securityName,
securityLevel, contextEngineId, contextName,
pduVersion, _, origPdu, maxSizeResponseScopedPDU,
statusInformation) = self.__pendingReqs[stateReference]
# Agent-side API complies with SMIv2
if messageProcessingModel == 0:
PDU = rfc2576.v2ToV1(PDU, origPdu)
# 3.2.6
try:
snmpEngine.msgAndPduDsp.returnResponsePdu(
snmpEngine,
messageProcessingModel,
securityModel,
securityName,
securityLevel,
contextEngineId,
contextName,
pduVersion,
PDU,
maxSizeResponseScopedPDU,
stateReference,
statusInformation
)
except error.StatusInformation:
debug.logger & debug.flagApp and debug.logger(
'sendPdu: stateReference %s, statusInformation %s' % (stateReference, sys.exc_info()[1]))
snmpSilentDrops, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMPv2-MIB',
'snmpSilentDrops')
snmpSilentDrops.syntax += 1
_getRequestType = rfc1905.GetRequestPDU.tagSet
_getNextRequestType = rfc1905.GetNextRequestPDU.tagSet
_setRequestType = rfc1905.SetRequestPDU.tagSet
_counter64Type = rfc1902.Counter64.tagSet
def releaseStateInformation(self, stateReference):
if stateReference in self.__pendingReqs:
del self.__pendingReqs[stateReference]
def processPdu(self, snmpEngine, messageProcessingModel, securityModel,
securityName, securityLevel, contextEngineId, contextName,
pduVersion, PDU, maxSizeResponseScopedPDU, stateReference):
# Agent-side API complies with SMIv2
if messageProcessingModel == 0:
origPdu = PDU
PDU = rfc2576.v1ToV2(PDU)
else:
origPdu = None
# 3.2.1
if (PDU.tagSet not in rfc3411.readClassPDUs and
PDU.tagSet not in rfc3411.writeClassPDUs):
raise error.ProtocolError('Unexpected PDU class %s' % PDU.tagSet)
# 3.2.2 --> no-op
# 3.2.4
rspPDU = v2c.apiPDU.getResponse(PDU)
statusInformation = {}
self.__pendingReqs[stateReference] = (
messageProcessingModel, securityModel, securityName,
securityLevel, contextEngineId, contextName, pduVersion,
rspPDU, origPdu, maxSizeResponseScopedPDU, statusInformation
)
# 3.2.5
varBinds = v2c.apiPDU.getVarBinds(PDU)
errorStatus, errorIndex = 'noError', 0
debug.logger & debug.flagApp and debug.logger(
'processPdu: stateReference %s, varBinds %s' % (stateReference, varBinds))
try:
self.handleMgmtOperation(snmpEngine, stateReference,
contextName, PDU,
(self.__verifyAccess, snmpEngine))
# SNMPv2 SMI exceptions
except pysnmp.smi.error.GenError:
errorIndication = sys.exc_info()[1]
debug.logger & debug.flagApp and debug.logger(
'processPdu: stateReference %s, errorIndication %s' % (stateReference, errorIndication))
if 'oid' in errorIndication:
# Request REPORT generation
statusInformation['oid'] = errorIndication['oid']
statusInformation['val'] = errorIndication['val']
# PDU-level SMI errors
except pysnmp.smi.error.NoAccessError:
errorStatus, errorIndex = 'noAccess', sys.exc_info()[1]['idx'] + 1
except pysnmp.smi.error.WrongTypeError:
errorStatus, errorIndex = 'wrongType', sys.exc_info()[1]['idx'] + 1
except pysnmp.smi.error.WrongLengthError:
errorStatus, errorIndex = 'wrongLength', sys.exc_info()[1]['idx'] + 1
except pysnmp.smi.error.WrongEncodingError:
errorStatus, errorIndex = 'wrongEncoding', sys.exc_info()[1]['idx'] + 1
except pysnmp.smi.error.WrongValueError:
errorStatus, errorIndex = 'wrongValue', sys.exc_info()[1]['idx'] + 1
except pysnmp.smi.error.NoCreationError:
errorStatus, errorIndex = 'noCreation', sys.exc_info()[1]['idx'] + 1
except pysnmp.smi.error.InconsistentValueError:
errorStatus, errorIndex = 'inconsistentValue', sys.exc_info()[1]['idx'] + 1
except pysnmp.smi.error.ResourceUnavailableError:
errorStatus, errorIndex = 'resourceUnavailable', sys.exc_info()[1]['idx'] + 1
except pysnmp.smi.error.CommitFailedError:
errorStatus, errorIndex = 'commitFailed', sys.exc_info()[1]['idx'] + 1
except pysnmp.smi.error.UndoFailedError:
errorStatus, errorIndex = 'undoFailed', sys.exc_info()[1]['idx'] + 1
except pysnmp.smi.error.AuthorizationError:
errorStatus, errorIndex = 'authorizationError', sys.exc_info()[1]['idx'] + 1
except pysnmp.smi.error.NotWritableError:
errorStatus, errorIndex = 'notWritable', sys.exc_info()[1]['idx'] + 1
except pysnmp.smi.error.InconsistentNameError:
errorStatus, errorIndex = 'inconsistentName', sys.exc_info()[1]['idx'] + 1
except pysnmp.smi.error.SmiError:
errorStatus, errorIndex = 'genErr', len(varBinds) and 1 or 0
except pysnmp.error.PySnmpError:
self.releaseStateInformation(stateReference)
return
else: # successful request processor must release state info
return
self.sendVarBinds(snmpEngine, stateReference, errorStatus,
errorIndex, varBinds)
self.releaseStateInformation(stateReference)
def __verifyAccess(self, name, syntax, idx, viewType, acCtx):
snmpEngine = acCtx
execCtx = snmpEngine.observer.getExecutionContext('rfc3412.receiveMessage:request')
(securityModel, securityName, securityLevel, contextName,
pduType) = (execCtx['securityModel'], execCtx['securityName'],
execCtx['securityLevel'], execCtx['contextName'],
execCtx['pdu'].getTagSet())
try:
snmpEngine.accessControlModel[self.acmID].isAccessAllowed(
snmpEngine, securityModel, securityName,
securityLevel, viewType, contextName, name
)
# Map ACM errors onto SMI ones
except error.StatusInformation:
statusInformation = sys.exc_info()[1]
debug.logger & debug.flagApp and debug.logger(
'__verifyAccess: name %s, statusInformation %s' % (name, statusInformation))
errorIndication = statusInformation['errorIndication']
# 3.2.5...
if (errorIndication == errind.noSuchView or
errorIndication == errind.noAccessEntry or
errorIndication == errind.noGroupName):
raise pysnmp.smi.error.AuthorizationError(name=name, idx=idx)
elif errorIndication == errind.otherError:
raise pysnmp.smi.error.GenError(name=name, idx=idx)
elif errorIndication == errind.noSuchContext:
snmpUnknownContexts, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
'__SNMP-TARGET-MIB', 'snmpUnknownContexts')
snmpUnknownContexts.syntax += 1
# Request REPORT generation
raise pysnmp.smi.error.GenError(name=name, idx=idx,
oid=snmpUnknownContexts.name,
val=snmpUnknownContexts.syntax)
elif errorIndication == errind.notInView:
return 1
else:
raise error.ProtocolError('Unknown ACM error %s' % errorIndication)
else:
# rfc2576: 4.1.2.1
if (securityModel == 1 and syntax is not None and
self._counter64Type == syntax.getTagSet() and
self._getNextRequestType == pduType):
# This will cause MibTree to skip this OID-value
raise pysnmp.smi.error.NoAccessError(name=name, idx=idx)
class GetCommandResponder(CommandResponderBase):
pduTypes = (rfc1905.GetRequestPDU.tagSet,)
# rfc1905: 4.2.1
def handleMgmtOperation(self, snmpEngine, stateReference,
contextName, PDU, acInfo):
(acFun, acCtx) = acInfo
# rfc1905: 4.2.1.1
mgmtFun = self.snmpContext.getMibInstrum(contextName).readVars
self.sendVarBinds(snmpEngine, stateReference, 0, 0,
mgmtFun(v2c.apiPDU.getVarBinds(PDU), (acFun, acCtx)))
self.releaseStateInformation(stateReference)
class NextCommandResponder(CommandResponderBase):
pduTypes = (rfc1905.GetNextRequestPDU.tagSet,)
# rfc1905: 4.2.2
def handleMgmtOperation(self, snmpEngine, stateReference,
contextName, PDU, acInfo):
(acFun, acCtx) = acInfo
# rfc1905: 4.2.2.1
mgmtFun = self.snmpContext.getMibInstrum(contextName).readNextVars
varBinds = v2c.apiPDU.getVarBinds(PDU)
while True:
rspVarBinds = mgmtFun(varBinds, (acFun, acCtx))
try:
self.sendVarBinds(snmpEngine, stateReference, 0, 0, rspVarBinds)
except error.StatusInformation:
idx = sys.exc_info()[1]['idx']
varBinds[idx] = (rspVarBinds[idx][0], varBinds[idx][1])
else:
break
self.releaseStateInformation(stateReference)
class BulkCommandResponder(CommandResponderBase):
pduTypes = (rfc1905.GetBulkRequestPDU.tagSet,)
maxVarBinds = 64
# rfc1905: 4.2.3
def handleMgmtOperation(self, snmpEngine, stateReference,
contextName, PDU, acInfo):
(acFun, acCtx) = acInfo
nonRepeaters = v2c.apiBulkPDU.getNonRepeaters(PDU)
if nonRepeaters < 0:
nonRepeaters = 0
maxRepetitions = v2c.apiBulkPDU.getMaxRepetitions(PDU)
if maxRepetitions < 0:
maxRepetitions = 0
reqVarBinds = v2c.apiPDU.getVarBinds(PDU)
N = min(int(nonRepeaters), len(reqVarBinds))
M = int(maxRepetitions)
R = max(len(reqVarBinds) - N, 0)
if R:
M = min(M, self.maxVarBinds // R)
debug.logger & debug.flagApp and debug.logger('handleMgmtOperation: N %d, M %d, R %d' % (N, M, R))
mgmtFun = self.snmpContext.getMibInstrum(contextName).readNextVars
if N:
rspVarBinds = mgmtFun(reqVarBinds[:N], (acFun, acCtx))
else:
rspVarBinds = []
varBinds = reqVarBinds[-R:]
while M and R:
rspVarBinds.extend(mgmtFun(varBinds, (acFun, acCtx)))
varBinds = rspVarBinds[-R:]
M -= 1
if len(rspVarBinds):
self.sendVarBinds(snmpEngine, stateReference, 0, 0, rspVarBinds)
self.releaseStateInformation(stateReference)
else:
raise pysnmp.smi.error.SmiError()
class SetCommandResponder(CommandResponderBase):
pduTypes = (rfc1905.SetRequestPDU.tagSet,)
# rfc1905: 4.2.5
def handleMgmtOperation(self, snmpEngine, stateReference,
contextName, PDU, acInfo):
(acFun, acCtx) = acInfo
mgmtFun = self.snmpContext.getMibInstrum(contextName).writeVars
# rfc1905: 4.2.5.1-13
try:
self.sendVarBinds(snmpEngine, stateReference, 0, 0,
mgmtFun(v2c.apiPDU.getVarBinds(PDU),
(acFun, acCtx)))
self.releaseStateInformation(stateReference)
except (pysnmp.smi.error.NoSuchObjectError,
pysnmp.smi.error.NoSuchInstanceError):
e = pysnmp.smi.error.NotWritableError()
e.update(sys.exc_info()[1])
raise e
|
