[AGENT++] Why is it possible to destroy an non existing row?

[Claus Klein]

Hi,

I can't understand why it should possible to delete a non existing row?

I have added this code to prevent this strange behavior:

int netSnmpHostsEntry::is_transition_ok(MibTable* table, MibTableRow* row, const Oidx& index,
                                        int currentStatus, int requestedStatus) {
    // The row 'row' with 'index' from 'table' (which will be 0 for local table)
    // is requested to change status. Accept or deny this state change here.
    //--AgentGen BEGIN=netSnmpHostsEntry::is_transition_ok

    if ((currentStatus == rowEmpty) && (requestedStatus == rowDestroy)) {
        std::cerr << BOOST_CURRENT_FUNCTION  << "(" << currentStatus << " -> "
                  << requestedStatus << ") This is not allowed!" << std::endl;
        return SNMP_ERROR_INCONSIST_VAL;
    }
...
}


Without this check the following happens:

Claus-Kleins-MacBook-Pro:agentproI12 clausklein$ snmptable -Cib -r0 -t10 localhost hoststable
SNMP table: NET-SNMP-EXAMPLES-MIB::netSnmpHostsTable

            index AddressType                                            Address     Storage RowStatus
     \"loopback\"        ipv6 "00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 " nonVolatile    active
    \"localhost\"        ipv4                                     "7F 00 00 01 " nonVolatile    active
\"broadcasthost\"        ipv4                                     "FF FF FF FF " nonVolatile    active

Claus-Kleins-MacBook-Pro:agentproI12 clausklein$ snmpset localhost netSnmpHostRowStatus.\"test\" = destroy
NET-SNMP-EXAMPLES-MIB::netSnmpHostRowStatus.\"test\" = INTEGER: destroy(6)

Claus-Kleins-MacBook-Pro:agentproI12 clausklein$ snmptable -Cib -r0 -t10 localhost hoststable
SNMP table: NET-SNMP-EXAMPLES-MIB::netSnmpHostsTable

            index AddressType                                            Address     Storage RowStatus
     \"loopback\"        ipv6 "00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 " nonVolatile    active
    \"localhost\"        ipv4                                     "7F 00 00 01 " nonVolatile    active
\"broadcasthost\"        ipv4                                     "FF FF FF FF " nonVolatile    active
         \"test\"           ?                                                  ? nonVolatile   destroy

Claus-Kleins-MacBook-Pro:agentproI12 clausklein$ snmpset localhost netSnmpHostRowStatus.\"test\" = destroy
Error in packet.
Reason: inconsistentValue (The set value is illegal or unsupported in some way)
Failed object: NET-SNMP-EXAMPLES-MIB::netSnmpHostRowStatus.\"test\"

Claus-Kleins-MacBook-Pro:agentproI12 clausklein$ 


... and the index is blocked with RowStatus "destroy" forever.

Tested with shared and non shared Tables; current net-snmp as agentX master and 

agent++v3.5.31
agentX++v1.4.18a
libdes-l-4.01a
snmp++v3.2.25

as agentX subagent.


//Regards
Claus