path: root/pysnmp/entity/rfc3413/ntforg.py

#
# This file is part of pysnmp software.
#
# Copyright (c) 2005-2019, Ilya Etingof <etingof@gmail.com>
# License: http://snmplabs.com/pysnmp/license.html
#
import sys
from pyasn1.compat.octets import null
from pysnmp.entity.rfc3413 import config
from pysnmp.proto.proxy import rfc2576
from pysnmp.proto import rfc3411
from pysnmp.proto.api import v2c
from pysnmp.proto import errind, error
from pysnmp.smi import view, rfc1902
from pysnmp import nextid
from pysnmp import debug

getNextHandle = nextid.Integer(0x7fffffff)


class NotificationOriginator(object):
    ACM_ID = 3  # default MIB access control method to use

    def __init__(self, **options):
        self.__pendingReqs = {}
        self.__pendingNotifications = {}
        self.snmpContext = options.pop('snmpContext', None)  # this is deprecated
        self.__options = options

    def processResponsePdu(self, snmpEngine, messageProcessingModel,
                           securityModel, securityName, securityLevel,
                           contextEngineId, contextName, pduVersion,
                           PDU, statusInformation, sendPduHandle, cbInfo):
        sendRequestHandle, cbFun, cbCtx = cbInfo

        # 3.3.6d
        if sendPduHandle not in self.__pendingReqs:
            raise error.ProtocolError('Missing sendPduHandle %s' % sendPduHandle)

        (origTransportDomain, origTransportAddress,
         origMessageProcessingModel, origSecurityModel,
         origSecurityName, origSecurityLevel, origContextEngineId,
         origContextName, origPdu, origTimeout,
         origRetryCount, origRetries, origDiscoveryRetries) = self.__pendingReqs.pop(sendPduHandle)

        snmpEngine.transportDispatcher.jobFinished(id(self))

        if statusInformation:
            debug.logger & debug.FLAG_APP and debug.logger(
                'processResponsePdu: sendRequestHandle %s, sendPduHandle %s statusInformation %s' % (
                    sendRequestHandle, sendPduHandle, statusInformation))

            errorIndication = statusInformation['errorIndication']

            if errorIndication in (errind.notInTimeWindow, errind.unknownEngineID):
                origDiscoveryRetries += 1
                origRetries = 0
            else:
                origDiscoveryRetries = 0
                origRetries += 1

            if origRetries > origRetryCount or origDiscoveryRetries > self.__options.get('discoveryRetries', 4):
                debug.logger & debug.FLAG_APP and debug.logger(
                    'processResponsePdu: sendRequestHandle %s, sendPduHandle %s retry count %d exceeded' % (
                        sendRequestHandle, sendPduHandle, origRetries))
                cbFun(snmpEngine, sendRequestHandle, errorIndication, None, cbCtx)
                return

            # Convert timeout in seconds into timeout in timer ticks
            timeoutInTicks = float(origTimeout) / 100 / snmpEngine.transportDispatcher.getTimerResolution()

            # User-side API assumes SMIv2
            if messageProcessingModel == 0:
                reqPDU = rfc2576.v2ToV1(origPdu)
                pduVersion = 0
            else:
                reqPDU = origPdu
                pduVersion = 1

            # 3.3.6a
            try:
                sendPduHandle = snmpEngine.msgAndPduDsp.sendPdu(
                    snmpEngine, origTransportDomain, origTransportAddress,
                    origMessageProcessingModel, origSecurityModel,
                    origSecurityName, origSecurityLevel,
                    origContextEngineId, origContextName, pduVersion,
                    reqPDU, True, timeoutInTicks, self.processResponsePdu,
                    (sendRequestHandle, cbFun, cbCtx)
                )
            except error.StatusInformation as exc:
                statusInformation = exc
                debug.logger & debug.FLAG_APP and debug.logger(
                    'processResponsePdu: sendRequestHandle %s: sendPdu() failed with %r ' % (
                        sendRequestHandle, statusInformation))
                cbFun(snmpEngine, sendRequestHandle,
                      statusInformation['errorIndication'], None, cbCtx)
                return

            snmpEngine.transportDispatcher.jobStarted(id(self))

            debug.logger & debug.FLAG_APP and debug.logger(
                'processResponsePdu: sendRequestHandle %s, sendPduHandle %s, timeout %d, retry %d of %d' % (
                    sendRequestHandle, sendPduHandle, origTimeout, origRetries, origRetryCount))

            # 3.3.6b
            self.__pendingReqs[sendPduHandle] = (
                origTransportDomain, origTransportAddress,
                origMessageProcessingModel, origSecurityModel,
                origSecurityName, origSecurityLevel,
                origContextEngineId, origContextName, origPdu,
                origTimeout, origRetryCount, origRetries, origDiscoveryRetries
            )
            return

        # 3.3.6c
        # User-side API assumes SMIv2
        if messageProcessingModel == 0:
            PDU = rfc2576.v1ToV2(PDU, origPdu)

        cbFun(snmpEngine, sendRequestHandle, None, PDU, cbCtx)

    def sendPdu(self, snmpEngine, targetName, contextEngineId,
                contextName, pdu, cbFun=None, cbCtx=None):
        (transportDomain, transportAddress, timeout,
         retryCount, params) = config.getTargetAddr(snmpEngine, targetName)

        (messageProcessingModel, securityModel, securityName,
         securityLevel) = config.getTargetParams(snmpEngine, params)

        # User-side API assumes SMIv2
        if messageProcessingModel == 0:
            reqPDU = rfc2576.v2ToV1(pdu)
            pduVersion = 0
        else:
            reqPDU = pdu
            pduVersion = 1

        # 3.3.5
        if reqPDU.tagSet in rfc3411.CONFIRMED_CLASS_PDUS:
            # Convert timeout in seconds into timeout in timer ticks
            timeoutInTicks = float(timeout) / 100 / snmpEngine.transportDispatcher.getTimerResolution()

            sendRequestHandle = getNextHandle()

            # 3.3.6a
            sendPduHandle = snmpEngine.msgAndPduDsp.sendPdu(
                snmpEngine, transportDomain, transportAddress,
                messageProcessingModel, securityModel, securityName,
                securityLevel, contextEngineId, contextName,
                pduVersion, reqPDU, True, timeoutInTicks,
                self.processResponsePdu, (sendRequestHandle, cbFun, cbCtx)
            )

            debug.logger & debug.FLAG_APP and debug.logger(
                'sendPdu: sendPduHandle %s, timeout %d' % (sendPduHandle, timeout))

            # 3.3.6b
            self.__pendingReqs[sendPduHandle] = (
                transportDomain, transportAddress, messageProcessingModel,
                securityModel, securityName, securityLevel, contextEngineId,
                contextName, pdu, timeout, retryCount, 0, 0
            )
            snmpEngine.transportDispatcher.jobStarted(id(self))
        else:
            snmpEngine.msgAndPduDsp.sendPdu(
                snmpEngine, transportDomain, transportAddress,
                messageProcessingModel, securityModel,
                securityName, securityLevel, contextEngineId,
                contextName, pduVersion, reqPDU, False
            )

            sendRequestHandle = None

            debug.logger & debug.FLAG_APP and debug.logger('sendPdu: message sent')

        return sendRequestHandle

    def processResponseVarBinds(self, snmpEngine, sendRequestHandle,
                                errorIndication, pdu, cbCtx):
        notificationHandle, cbFun, cbCtx = cbCtx

        self.__pendingNotifications[notificationHandle].remove(sendRequestHandle)

        debug.logger & debug.FLAG_APP and debug.logger(
            'processResponseVarBinds: notificationHandle %s, sendRequestHandle %s, errorIndication %s, pending requests %s' % (
                notificationHandle, sendRequestHandle, errorIndication, self.__pendingNotifications[notificationHandle]))

        if not self.__pendingNotifications[notificationHandle]:
            debug.logger & debug.FLAG_APP and debug.logger(
                'processResponseVarBinds: notificationHandle %s, sendRequestHandle %s -- completed' % (
                    notificationHandle, sendRequestHandle))
            del self.__pendingNotifications[notificationHandle]
            cbFun(snmpEngine, sendRequestHandle, errorIndication,
                  pdu and v2c.apiPDU.getErrorStatus(pdu) or 0,
                  pdu and v2c.apiPDU.getErrorIndex(pdu, muteErrors=True) or 0,
                  pdu and v2c.apiPDU.getVarBinds(pdu) or (),
                  cbCtx)

    #
    # Higher-level API to Notification Originator. Supports multiple
    # targets, automatic var-binding formation and is fully LCD-driven.
    #
    def sendVarBinds(self, snmpEngine, notificationTarget, contextEngineId,
                     contextName, varBinds=(), cbFun=None, cbCtx=None):
        debug.logger & debug.FLAG_APP and debug.logger(
            'sendVarBinds: notificationTarget %s, contextEngineId %s, contextName "%s", varBinds %s' % (
                notificationTarget, contextEngineId or '<default>', contextName, varBinds))

        if contextName:
            __SnmpAdminString, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
                'SNMP-FRAMEWORK-MIB', 'SnmpAdminString')
            contextName = __SnmpAdminString(contextName)

        # 3.3
        (notifyTag, notifyType) = config.getNotificationInfo(snmpEngine, notificationTarget)

        notificationHandle = getNextHandle()

        debug.logger & debug.FLAG_APP and debug.logger(
            'sendVarBinds: notificationHandle %s, notifyTag %s, notifyType %s' % (
                notificationHandle, notifyTag, notifyType))

        varBinds = [(v2c.ObjectIdentifier(x), y) for x, y in varBinds]

        # 3.3.2 & 3.3.3
        snmpTrapOID, sysUpTime = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMPv2-MIB',
                                                                                                       'snmpTrapOID',
                                                                                                       'sysUpTime')

        for idx in range(len(varBinds)):
            if idx and varBinds[idx][0] == sysUpTime.getName():
                if varBinds[0][0] == sysUpTime.getName():
                    varBinds[0] = varBinds[idx]
                else:
                    varBinds.insert(0, varBinds[idx])
                    del varBinds[idx]

            if varBinds[0][0] != sysUpTime.getName():
                varBinds.insert(0, (v2c.ObjectIdentifier(sysUpTime.getName()),
                                    sysUpTime.getSyntax().clone()))

        if len(varBinds) < 2 or varBinds[1][0] != snmpTrapOID.getName():
            varBinds.insert(1, (v2c.ObjectIdentifier(snmpTrapOID.getName()),
                                snmpTrapOID.getSyntax()))

        sendRequestHandle = -1

        debug.logger & debug.FLAG_APP and debug.logger('sendVarBinds: final varBinds %s' % (varBinds,))

        for targetAddrName in config.getTargetNames(snmpEngine, notifyTag):
            (transportDomain, transportAddress, timeout,
             retryCount, params) = config.getTargetAddr(snmpEngine,
                                                        targetAddrName)
            (messageProcessingModel, securityModel, securityName,
             securityLevel) = config.getTargetParams(snmpEngine, params)

            # 3.3.1 XXX
            # XXX filtering's yet to be implemented
            #             filterProfileName = config.getNotifyFilterProfile(params)

            #             (filterSubtree, filterMask,
            #              filterType) = config.getNotifyFilter(filterProfileName)

            debug.logger & debug.FLAG_APP and debug.logger(
                'sendVarBinds: notificationHandle %s, notifyTag %s yields: transportDomain %s, transportAddress %r, securityModel %s, securityName %s, securityLevel %s' % (
                    notificationHandle, notifyTag, transportDomain, transportAddress, securityModel,
                    securityName, securityLevel))

            for varName, varVal in varBinds:
                if varName in (sysUpTime.name, snmpTrapOID.name):
                    continue
                try:
                    snmpEngine.accessControlModel[self.ACM_ID].isAccessAllowed(
                        snmpEngine, securityModel, securityName,
                        securityLevel, 'notify', contextName, varName
                    )

                    debug.logger & debug.FLAG_APP and debug.logger(
                        'sendVarBinds: ACL succeeded for OID %s securityName %s' % (varName, securityName))

                except error.StatusInformation:
                    debug.logger & debug.FLAG_APP and debug.logger(
                        'sendVarBinds: ACL denied access for OID %s securityName %s, droppping notification' % (
                            varName, securityName))
                    return

            # 3.3.4
            if notifyType == 1:
                pdu = v2c.SNMPv2TrapPDU()
            elif notifyType == 2:
                pdu = v2c.InformRequestPDU()
            else:
                raise error.ProtocolError('Unknown notify-type %r', notifyType)

            v2c.apiPDU.setDefaults(pdu)
            v2c.apiPDU.setVarBinds(pdu, varBinds)

            # 3.3.5
            try:
                sendRequestHandle = self.sendPdu(
                    snmpEngine, targetAddrName, contextEngineId,
                    contextName, pdu, self.processResponseVarBinds,
                    (notificationHandle, cbFun, cbCtx)
                )

            except error.StatusInformation as exc:
                statusInformation = exc
                debug.logger & debug.FLAG_APP and debug.logger(
                    'sendVarBinds: sendRequestHandle %s: sendPdu() failed with %r' % (
                        sendRequestHandle, statusInformation))
                if notificationHandle not in self.__pendingNotifications or \
                        not self.__pendingNotifications[notificationHandle]:
                    if notificationHandle in self.__pendingNotifications:
                        del self.__pendingNotifications[notificationHandle]
                    if cbFun:
                        cbFun(snmpEngine, notificationHandle,
                              statusInformation['errorIndication'], 0, 0, (),
                              cbCtx)
                return notificationHandle

            debug.logger & debug.FLAG_APP and debug.logger(
                'sendVarBinds: notificationHandle %s, sendRequestHandle %s, timeout %d' % (
                    notificationHandle, sendRequestHandle, timeout))

            if notifyType == 2:
                if notificationHandle not in self.__pendingNotifications:
                    self.__pendingNotifications[notificationHandle] = set()
                self.__pendingNotifications[notificationHandle].add(sendRequestHandle)

        debug.logger & debug.FLAG_APP and debug.logger(
            'sendVarBinds: notificationHandle %s, sendRequestHandle %s, notification(s) sent' % (
                notificationHandle, sendRequestHandle))

        return notificationHandle

# XXX
# move/group/implement config setting/retrieval at a stand-alone module