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Diffstat (limited to 'examples/v1arch/asyncore/manager/cmdgen/get-v2c-udp-broadcast-agent-discovery.py')
-rw-r--r-- | examples/v1arch/asyncore/manager/cmdgen/get-v2c-udp-broadcast-agent-discovery.py | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/examples/v1arch/asyncore/manager/cmdgen/get-v2c-udp-broadcast-agent-discovery.py b/examples/v1arch/asyncore/manager/cmdgen/get-v2c-udp-broadcast-agent-discovery.py new file mode 100644 index 0000000..cd8c3c9 --- /dev/null +++ b/examples/v1arch/asyncore/manager/cmdgen/get-v2c-udp-broadcast-agent-discovery.py @@ -0,0 +1,99 @@ +""" +Broadcast SNMP message (IPv4) ++++++++++++++++++++++++++++++ + +Send SNMP GET request to broadcast address and wait for respons(es): + +* with SNMPv2c, community 'public' +* over IPv4/UDP +* to all Agents via broadcast address 255.255.255.255:161 +* for OIDs in tuple form + +Here we send out a single SNMP request and wait for potentially many SNMP +responses from multiple SNMP Agents listening in local broadcast domain. +Since we can't predict the exact number of Agents responding, this script +just waits for arbitrary time for collecting all responses. This technology +is also known as SNMP-based discovery. + +This script performs similar to the following Net-SNMP command: + +| $ snmpget -v2c -c public -ObentU 255.255.255.255 1.3.6.1.2.1.1.1.0 1.3.6.1.2.1.1.3.0 + +"""# +from pysnmp.carrier.asyncore.dispatch import AsyncoreDispatcher +from pysnmp.carrier.asyncore.dgram import udp +from pyasn1.codec.ber import encoder, decoder +from pysnmp.proto import api +from time import time + +# Broadcast manager settings +maxWaitForResponses = 5 +maxNumberResponses = 10 + +# Protocol version to use +#pMod = api.protoModules[api.protoVersion1] +pMod = api.protoModules[api.protoVersion2c] + +# Build PDU +reqPDU = pMod.GetRequestPDU() +pMod.apiPDU.setDefaults(reqPDU) +pMod.apiPDU.setVarBinds( + reqPDU, ( ('1.3.6.1.2.1.1.1.0', pMod.Null('')), + ('1.3.6.1.2.1.1.3.0', pMod.Null('')) ) + ) + +# Build message +reqMsg = pMod.Message() +pMod.apiMessage.setDefaults(reqMsg) +pMod.apiMessage.setCommunity(reqMsg, 'public') +pMod.apiMessage.setPDU(reqMsg, reqPDU) + +startedAt = time() + +class StopWaiting(Exception): pass + +def cbTimerFun(timeNow): + if timeNow - startedAt > maxWaitForResponses: + raise StopWaiting() + +def cbRecvFun(transportDispatcher, transportDomain, transportAddress, + wholeMsg, reqPDU=reqPDU): + while wholeMsg: + rspMsg, wholeMsg = decoder.decode(wholeMsg, asn1Spec=pMod.Message()) + rspPDU = pMod.apiMessage.getPDU(rspMsg) + # Match response to request + if pMod.apiPDU.getRequestID(reqPDU)==pMod.apiPDU.getRequestID(rspPDU): + # Check for SNMP errors reported + errorStatus = pMod.apiPDU.getErrorStatus(rspPDU) + if errorStatus: + print(errorStatus.prettyPrint()) + else: + for oid, val in pMod.apiPDU.getVarBinds(rspPDU): + print('%s = %s' % (oid.prettyPrint(), val.prettyPrint())) + transportDispatcher.jobFinished(1) + return wholeMsg + +transportDispatcher = AsyncoreDispatcher() + +transportDispatcher.registerRecvCbFun(cbRecvFun) +transportDispatcher.registerTimerCbFun(cbTimerFun) + +# UDP/IPv4 +udpSocketTransport = udp.UdpSocketTransport().openClientMode().enableBroadcast() +transportDispatcher.registerTransport(udp.domainName, udpSocketTransport) + +# Pass message to dispatcher +transportDispatcher.sendMessage( + encoder.encode(reqMsg), udp.domainName, ('255.255.255.255', 161) +) + +# wait for a maximum of 10 responses or time out +transportDispatcher.jobStarted(1, maxNumberResponses) + +# Dispatcher will finish as all jobs counter reaches zero +try: + transportDispatcher.runDispatcher() +except StopWaiting: + transportDispatcher.closeDispatcher() +else: + raise |