[SNMP4J] Difficulty with vacmViewExcluded
m k
mkeller01 at hotmail.com
Fri Oct 25 17:11:29 CEST 2013
Hello,
I've been trying to restrict the user's read view of a subtree, with the ultimate goal of filtering out everything from 1.3.6.1.6.3.16.*, so the user could see everything but that VACM information. However, I can't seem to limit my restriction. As a small experiment, I tried to filter out sysDescr.0, while leaving everything else readable, as below:
I added the view tree family like so:
vacm.addViewTreeFamily(new OctetString("fullReadView"), new OID("1.3.6.1.2.1.1.1.0"),
new OctetString(), VacmMIB.vacmViewExcluded,
StorageType.nonVolatile);
Now, when the user attempts to access sysDescr.0, the following debug info shows they are denied access (as I expected):
23829 [DefaultUDPTransportMapping_127.0.0.1/161] DEBUG org.snmp4j.transport.DefaultUdpTransportMapping - Received message from localhost/127.0.0.1/50196 with length 43: 30:29:02:01:01:04:06:70:75:62:6c:69:63:a0:1c:02:04:4d:85:9b:1c:02:01:00:02:01:00:30:0e:30:0c:06:08:2b:06:01:02:01:01:01:00:05:00
23842 [DefaultUDPTransportMapping_127.0.0.1/161] DEBUG org.snmp4j.Snmp - Fire process PDU event: CommandResponderEvent[securityModel=2, securityLevel=1, maxSizeResponsePDU=65535, pduHandle=PduHandle[1300601628], stateReference=StateReference[msgID=0,pduHandle=PduHandle[1300601628],securityEngineID=null,securityModel=null,securityName=public,securityLevel=1,contextEngineID=null,contextName=null,retryMsgIDs=null], pdu=GET[requestID=1300601628, errorStatus=Success(0), errorIndex=0, VBS[1.3.6.1.2.1.1.1.0 = Null]], messageProcessingModel=1, securityName=public, processed=false, peerAddress=127.0.0.1/50196, transportMapping=org.snmp4j.transport.DefaultUdpTransportMapping at 11505881, tmStateReference=null]
23843 [DefaultUDPTransportMapping_127.0.0.1/161] DEBUG org.snmp4j.agent.mo.snmp.SnmpCommunityMIB - Looking up coexistence info for 'public'
23845 [DefaultUDPTransportMapping_127.0.0.1/161] DEBUG org.snmp4j.agent.mo.snmp.SnmpCommunityMIB - Found coexistence info for 'public'=CoexistenceInfo[securityName=v1v2User,contextEngineID=80:00:13:70:01:0a:0a:65:24,contextName=,transportTag=]
23845 [DefaultUDPTransportMapping_127.0.0.1/161] DEBUG org.snmp4j.agent.mo.snmp.SnmpCommunityMIB - Address 127.0.0.1/50196 passes filter, because source address filtering is disabled
23851 [RequestPool.0] DEBUG org.snmp4j.agent.mo.snmp.VacmMIB - Found group name 'v1v2ReadOnly' for secName 'v1v2User' and secModel 2
23853 [RequestPool.0] DEBUG org.snmp4j.agent.mo.snmp.VacmMIB - Got views [DefaultMOMutableRow2PC[index=12.118.49.118.50.82.101.97.100.79.110.108.121.0.0.1,values=[1, fullReadView, restrictedWriteView, fullNotifyView, 3, 1]] for group name 'v1v2ReadOnly'
23853 [RequestPool.0] DEBUG org.snmp4j.agent.mo.snmp.VacmMIB - Matching against access entry DefaultMOMutableRow2PC[index=12.118.49.118.50.82.101.97.100.79.110.108.121.0.0.1,values=[1, fullReadView, restrictedWriteView, fullNotifyView, 3, 1] with exactContextMatch=true, prefixMatch=false, matchSecModel=true and matchSecLevel=true
23854 [RequestPool.0] DEBUG org.snmp4j.agent.mo.snmp.VacmMIB - Matching view found for group name 'v1v2ReadOnly' is 'fullReadView'
23859 [RequestPool.0] DEBUG org.snmp4j.agent.request.SnmpRequest - Created subrequest 0 with scope org.snmp4j.agent.DefaultMOContextScope[context=,lowerBound=1.3.6.1.2.1.1.1.0,lowerIncluded=true,upperBound=1.3.6.1.2.1.1.1.0,upperIncluded=true] from 1.3.6.1.2.1.1.1.0 = Null
23860 [RequestPool.0] DEBUG org.snmp4j.agent.request.SnmpRequest - SnmpSubRequests initialized: [org.snmp4j.agent.request.SnmpRequest$SnmpSubRequest[scope=org.snmp4j.agent.DefaultMOContextScope[context=,lowerBound=1.3.6.1.2.1.1.1.0,lowerIncluded=true,upperBound=1.3.6.1.2.1.1.1.0,upperIncluded=true],vb=1.3.6.1.2.1.1.1.0 = Null,status=org.snmp4j.agent.request.RequestStatus at 417f6125,query=null,index=0,targetMO=null]]
23862 [RequestPool.0] DEBUG org.snmp4j.agent.mo.snmp.VacmMIB - Access denied for view 'fullReadView' by subtree 1.3.6.1.2.1.1.1.0 for OID 1.3.6.1.2.1.1.1.0
23864 [RequestPool.0] DEBUG org.snmp4j.transport.DefaultUdpTransportMapping - Sending message to 127.0.0.1/50196 with length 43: 30:29:02:01:01:04:06:70:75:62:6c:69:63:a2:1c:02:04:4d:85:9b:1c:02:01:00:02:01:00:30:0e:30:0c:06:08:2b:06:01:02:01:01:01:00:80:00
However, when the user attempts to access the very next OID, which I did not intend to block, this is the result:
82799 [DefaultUDPTransportMapping_127.0.0.1/161] DEBUG org.snmp4j.transport.DefaultUdpTransportMapping - Received message from localhost/127.0.0.1/58177 with length 43: 30:29:02:01:01:04:06:70:75:62:6c:69:63:a0:1c:02:04:4d:85:9b:1f:02:01:00:02:01:00:30:0e:30:0c:06:08:2b:06:01:02:01:01:02:00:05:00
82800 [DefaultUDPTransportMapping_127.0.0.1/161] DEBUG org.snmp4j.Snmp - Fire process PDU event: CommandResponderEvent[securityModel=2, securityLevel=1, maxSizeResponsePDU=65535, pduHandle=PduHandle[1300601631], stateReference=StateReference[msgID=0,pduHandle=PduHandle[1300601631],securityEngineID=null,securityModel=null,securityName=public,securityLevel=1,contextEngineID=null,contextName=null,retryMsgIDs=null], pdu=GET[requestID=1300601631, errorStatus=Success(0), errorIndex=0, VBS[1.3.6.1.2.1.1.2.0 = Null]], messageProcessingModel=1, securityName=public, processed=false, peerAddress=127.0.0.1/58177, transportMapping=org.snmp4j.transport.DefaultUdpTransportMapping at 11505881, tmStateReference=null]
82800 [DefaultUDPTransportMapping_127.0.0.1/161] DEBUG org.snmp4j.agent.mo.snmp.SnmpCommunityMIB - Looking up coexistence info for 'public'
82801 [DefaultUDPTransportMapping_127.0.0.1/161] DEBUG org.snmp4j.agent.mo.snmp.SnmpCommunityMIB - Found coexistence info for 'public'=CoexistenceInfo[securityName=v1v2User,contextEngineID=80:00:13:70:01:0a:0a:65:24,contextName=,transportTag=]
82801 [DefaultUDPTransportMapping_127.0.0.1/161] DEBUG org.snmp4j.agent.mo.snmp.SnmpCommunityMIB - Address 127.0.0.1/58177 passes filter, because source address filtering is disabled
82801 [RequestPool.0] DEBUG org.snmp4j.agent.mo.snmp.VacmMIB - Found group name 'v1v2ReadOnly' for secName 'v1v2User' and secModel 2
82802 [RequestPool.0] DEBUG org.snmp4j.agent.mo.snmp.VacmMIB - Got views [DefaultMOMutableRow2PC[index=12.118.49.118.50.82.101.97.100.79.110.108.121.0.0.1,values=[1, fullReadView, restrictedWriteView, fullNotifyView, 3, 1]] for group name 'v1v2ReadOnly'
82802 [RequestPool.0] DEBUG org.snmp4j.agent.mo.snmp.VacmMIB - Matching against access entry DefaultMOMutableRow2PC[index=12.118.49.118.50.82.101.97.100.79.110.108.121.0.0.1,values=[1, fullReadView, restrictedWriteView, fullNotifyView, 3, 1] with exactContextMatch=true, prefixMatch=false, matchSecModel=true and matchSecLevel=true
82803 [RequestPool.0] DEBUG org.snmp4j.agent.mo.snmp.VacmMIB - Matching view found for group name 'v1v2ReadOnly' is 'fullReadView'
82803 [RequestPool.0] DEBUG org.snmp4j.agent.request.SnmpRequest - Created subrequest 0 with scope org.snmp4j.agent.DefaultMOContextScope[context=,lowerBound=1.3.6.1.2.1.1.2.0,lowerIncluded=true,upperBound=1.3.6.1.2.1.1.2.0,upperIncluded=true] from 1.3.6.1.2.1.1.2.0 = Null
82803 [RequestPool.0] DEBUG org.snmp4j.agent.request.SnmpRequest - SnmpSubRequests initialized: [org.snmp4j.agent.request.SnmpRequest$SnmpSubRequest[scope=org.snmp4j.agent.DefaultMOContextScope[context=,lowerBound=1.3.6.1.2.1.1.2.0,lowerIncluded=true,upperBound=1.3.6.1.2.1.1.2.0,upperIncluded=true],vb=1.3.6.1.2.1.1.2.0 = Null,status=org.snmp4j.agent.request.RequestStatus at 316ce88a,query=null,index=0,targetMO=null]]
82804 [RequestPool.0] DEBUG org.snmp4j.transport.DefaultUdpTransportMapping - Sending message to 127.0.0.1/58177 with length 43: 30:29:02:01:01:04:06:70:75:62:6c:69:63:a2:1c:02:04:4d:85:9b:1f:02:01:00:02:01:00:30:0e:30:0c:06:08:2b:06:01:02:01:01:02:00:80:00
So, while they are not explicitly denied, it's the same failure result as if they were. To be sure, if I change the previous code to this below, both OIDs can be accessed and retrieved perfectly:
// Works fine, but no restriction.
vacm.addViewTreeFamily(new OctetString("fullReadView"), new OID("1.3"),
new OctetString(), VacmMIB.vacmViewIncluded,
StorageType.nonVolatile);
...
What might the problem be here, and how can I achieve the restriction I am looking for? By the way, I'm using snmp4j-agent-2.0.10a.
Thanks for your help
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