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"""
Pull MIB subtree
++++++++++++++++
Send a series of SNMP GETNEXT requests
* with SNMPv3 with user 'usr-none-none', no auth and no privacy protocols
* over IPv4/UDP
* to an Agent at 127.0.0.1:161
* for an OID in string form
* stop whenever received OID goes out of initial prefix (it may be a table)
This script performs similar to the following Net-SNMP command:
| $ snmpwalk -v3 -l noAuthNoPriv -u usr-none-none -ObentU 127.0.0.1:161 1.3.6.1.2.1.1
""" #
from pysnmp.entity import engine, config
from pysnmp.carrier.asyncio.dgram import udp
from pysnmp.entity.rfc3413 import cmdgen
from pysnmp.proto import rfc1902
# Initial OID prefix
initialOID = rfc1902.ObjectName("1.3.6.1.2.1.1")
# Create SNMP engine instance
snmpEngine = engine.SnmpEngine()
#
# SNMPv3/USM setup
#
# user: usr-none-none, auth: none, priv: none
config.add_v3_user(
snmpEngine,
"usr-none-none",
)
config.add_target_parameters(snmpEngine, "my-creds", "usr-none-none", "noAuthNoPriv")
#
# Setup transport endpoint and bind it with security settings yielding
# a target name
#
# UDP/IPv4
config.add_transport(
snmpEngine, udp.DOMAIN_NAME, udp.UdpAsyncioTransport().open_client_mode()
)
config.add_target_address(
snmpEngine, "my-router", udp.DOMAIN_NAME, ("127.0.0.1", 161), "my-creds"
)
# Error/response receiver
# noinspection PyUnusedLocal,PyUnusedLocal,PyUnusedLocal
def cbFun(
snmpEngine,
sendRequestHandle,
errorIndication,
errorStatus,
errorIndex,
varBindTable,
cbCtx,
):
if errorIndication:
print(errorIndication)
return
if errorStatus:
print(
f"{errorStatus.prettyPrint()} at {varBindTable[-1][int(errorIndex) - 1][0] if errorIndex else '?'}"
)
return # stop on error
for varBindRow in varBindTable:
for oid, val in varBindRow:
if initialOID.isPrefixOf(oid):
print(f"{oid.prettyPrint()} = {val.prettyPrint()}")
else:
return False # signal dispatcher to stop
return True # signal dispatcher to continue
# Prepare initial request to be sent
cmdgen.NextCommandGenerator().send_varbinds(
snmpEngine,
"my-router",
None,
"", # contextEngineId, contextName
[(initialOID, None)],
cbFun,
)
# Run I/O dispatcher which would send pending queries and process responses
snmpEngine.open_dispatcher(3)
snmpEngine.close_dispatcher()
|
