1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
|
"""
Walk Agent MIB (SNMPv1)
+++++++++++++++++++++++
Perform SNMP GETNEXT operation with the following options:
* with SNMPv1, community 'public'
* over IPv4/UDP
* to an Agent at 195.218.195.228:161
* for OID in tuple form
This script performs similar to the following Net-SNMP command:
| $ snmpwalk -v1 -c public -ObentU 195.218.195.228 1.3.6
"""#
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
# Protocol version to use
pMod = api.protoModules[api.protoVersion1]
#pMod = api.protoModules[api.protoVersion2c]
# SNMP table header
headVars = [ pMod.ObjectIdentifier((1,3,6)) ]
# Build PDU
reqPDU = pMod.GetNextRequestPDU()
pMod.apiPDU.setDefaults(reqPDU)
pMod.apiPDU.setVarBinds(reqPDU, [ (x, pMod.null) for x in headVars ])
# Build message
reqMsg = pMod.Message()
pMod.apiMessage.setDefaults(reqMsg)
pMod.apiMessage.setCommunity(reqMsg, 'public')
pMod.apiMessage.setPDU(reqMsg, reqPDU)
startedAt = time()
def cbTimerFun(timeNow):
if timeNow - startedAt > 3:
raise Exception("Request timed out")
def cbRecvFun(transportDispatcher, transportDomain, transportAddress,
wholeMsg, reqPDU=reqPDU, headVars=headVars):
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 and errorStatus != 2:
raise Exception(errorStatus)
# Format var-binds table
varBindTable = pMod.apiPDU.getVarBindTable(reqPDU, rspPDU)
# Report SNMP table
for tableRow in varBindTable:
for name, val in tableRow:
print('from: %s, %s = %s' % (
transportAddress, name.prettyPrint(), val.prettyPrint()
)
)
# Stop on EOM
for oid, val in varBindTable[-1]:
if not isinstance(val, pMod.Null):
break
else:
transportDispatcher.jobFinished(1)
# Generate request for next row
pMod.apiPDU.setVarBinds(
reqPDU, [ (x, pMod.null) for x,y in varBindTable[-1] ]
)
pMod.apiPDU.setRequestID(reqPDU, pMod.getNextRequestID())
transportDispatcher.sendMessage(
encoder.encode(reqMsg), transportDomain, transportAddress
)
global startedAt
if time() - startedAt > 3:
raise Exception('Request timed out')
startedAt = time()
return wholeMsg
transportDispatcher = AsyncoreDispatcher()
transportDispatcher.registerRecvCbFun(cbRecvFun)
transportDispatcher.registerTimerCbFun(cbTimerFun)
transportDispatcher.registerTransport(
udp.domainName, udp.UdpSocketTransport().openClientMode()
)
transportDispatcher.sendMessage(
encoder.encode(reqMsg), udp.domainName, ('demo.snmplabs.com', 161)
)
transportDispatcher.jobStarted(1)
transportDispatcher.runDispatcher()
transportDispatcher.closeDispatcher()
|
