"""
Fetch scalar and table variables
++++++++++++++++++++++++++++++++

Send a series of SNMP GETBULK requests with the following options:

* with SNMPv3 with user 'usr-md5-des', MD5 auth and DES privacy protocols
* over IPv4/UDP
* to an Agent at 104.236.166.95:161
* with values non-repeaters = 1, max-repetitions = 25
* for two OIDs in tuple form (first OID is non-repeating)
* stop on end-of-mib condition for both OIDs

This script performs similar to the following Net-SNMP command:

| $ snmpbulkwalk -v3 -l authPriv -u usr-md5-des -A authkey1 -X privkey1 -C n1 -C r25 -ObentU 104.236.166.95 1.3.6.1.2.1.1 1.3.6.1.4.1.1

"""#
from pysnmp.entity import engine, config
from pysnmp.entity.rfc3413 import cmdgen
from pysnmp.carrier.asyncore.dgram import udp

# Create SNMP engine instance
snmpEngine = engine.SnmpEngine()

#
# SNMPv3/USM setup
#

# user: usr-md5-des, auth: MD5, priv DES
config.addV3User(
    snmpEngine, 'usr-md5-des',
    config.usmHMACMD5AuthProtocol, 'authkey1',
    config.usmDESPrivProtocol, 'privkey1'
)
config.addTargetParams(snmpEngine, 'my-creds', 'usr-md5-des', 'authPriv')

#
# Setup transport endpoint and bind it with security settings yielding
# a target name
#

# UDP/IPv4
config.addTransport(
    snmpEngine,
    udp.domainName,
    udp.UdpSocketTransport().openClientMode()
)
config.addTargetAddr(
    snmpEngine, 'my-router',
    udp.domainName, ('104.236.166.95', 161),
    'my-creds'
)


# Error/response receiver
# noinspection PyUnusedLocal,PyUnusedLocal,PyUnusedLocal
def cbFun(snmpEngine, sendRequesthandle, errorIndication,
          errorStatus, errorIndex, varBindTable, cbCtx):
    if errorIndication:
        print(errorIndication)
        return  # stop on error
    if errorStatus:
        print('%s at %s' % (errorStatus.prettyPrint(),
                            errorIndex and varBindTable[-1][int(errorIndex) - 1][0] or '?'))
        return  # stop on error
    for varBindRow in varBindTable:
        for oid, val in varBindRow:
            print('%s = %s' % (oid.prettyPrint(), val.prettyPrint()))
    return True  # signal dispatcher to continue walking


# Prepare initial request to be sent
cmdgen.BulkCommandGenerator().sendVarBinds(
    snmpEngine,
    'my-router',
    None, '',  # contextEngineId, contextName
    0, 25,  # non-repeaters, max-repetitions
    (((1, 3, 6, 1, 2, 1, 1), None),
     ((1, 3, 6, 1, 4, 1, 1), None)),
    cbFun
)

# Run I/O dispatcher which would send pending queries and process responses
snmpEngine.transportDispatcher.runDispatcher()