[AGENT++] illegal value at RowStatus after commitFailed

[Claus Klein]

Hi Frank,

> On 11 Apr 2015, at 16:26, Frank Fock <fock at agentpp.com> wrote:
> 
> Hi Claus,
> 
> The code of snmpRowStatus::unset() is correct as it is. If there is no undo value (undo == NULL)
> the undo cannot fail because there is nothing to undo.
OK, I agree.

> The problem with the row creation is caused something else. If the row creation fails, the new
> (intermediate) row has to be deleted (not added) to the table, but that works only if an
> undo value had been set.
That was my expectation.

> 
> In your cause this seems not to be happened. Why?
> A possible cause could be an overwriting of the snmpRowStatus::set method in a snmpRowStatus
> sub-class.
> Other causes have to be found or sorted out by debugging the code.
The problem occurred because the call to netSnmpExampleInteger::set() fails (hard coded for demo).

int netSnmpExampleInteger::set(const Vbx& vb)
{
    //--AgentGen BEGIN=netSnmpExampleInteger::set
	return SNMP_ERROR_AUTH_ERR;	//FIXME only for test
    //--AgentGen END
#ifdef MIB_TRACE
    std::cerr << BOOST_CURRENT_FUNCTION << std::endl;   // XXX
#endif // MIB_TRACE
    return MibLeaf::set(vb);
}

int netSnmpExampleInteger::commit_set_request(Request* req, int ind)
{
    //--AgentGen BEGIN=netSnmpExampleInteger::commit_set_request
    return SNMP_ERROR_COMITFAIL; // FIXME READONLY for test!
    //--AgentGen END
#ifdef MIB_TRACE
    std::cerr << BOOST_CURRENT_FUNCTION << std::endl;   // XXX
#endif // MIB_TRACE
    int status = MibLeaf::commit_set_request(req, ind);
    //--AgentGen BEGIN=netSnmpExampleInteger::commit_set_request2
    //--AgentGen END
    return status;
}


A general question:
When should I write to the HW, file, driver or what ever is below the MIB entry?

I use the set() method. But in our project, this may fail in some cases!

Best regards
Claus


> 
> Best regards,
> Frank
> 
> 
> Am 08.04.2015 um 23:20 schrieb Claus Klein:
>> Hi all,
>> 
>> I found a problem with the table RowStatus and snmpRowStatus::unset():
>> 
>> Claus-MBP:AgentPro clausklein$ snmpset -r0 -t10 -v3 -u unsecureUser -n subagent localhost:4700 'netSnmpHostRowStatus."test2"' = createAndGo \
>>     'netSnmpHostAddressType."test2"' = ipv4 'netSnmpHostAddress."test2"' x 7F000002  netSnmpExampleInteger.0 = 1
>> Error in packet.
>> Reason: commitFailed
>> Failed object: NET-SNMP-EXAMPLES-MIB::netSnmpExampleInteger.0
>> 
>> Claus-MBP:AgentPro clausklein$ snmptable -Cib -r0 -t10 -v3 -u unsecureUser -n subagent localhost:4700 netSnmpHostsTable
>> SNMP table: NET-SNMP-EXAMPLES-MIB::netSnmpHostsTable
>> 
>>             index AddressType                                            Address     Storage RowStatus
>>         \"nmsv6\"        ipv6 "00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 " nonVolatile    active
>>         \"test2\"     unknown                                                 "" nonVolatile         0
>>     \"localhost\"        ipv6 "00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 " nonVolatile    active
>> \"broadcasthost\"        ipv4                                     "FF FF FF FF " nonVolatile    active
>> Claus-MBP:AgentPro clausklein$
>> 
>> The undo ptr is NULL in this case and the row left in an illegal state?
>> By the way, older versions of agent++ lib use this NULL pointer and crash!
>> 
>> Is this a BUG or a feature?
>> 
>> Should the code be like this:
>> diff --git a/agent++/src/mib.cpp b/agent++/src/mib.cpp
>> index 5d41353..64b57be 100644
>> --- a/agent++/src/mib.cpp
>> +++ b/agent++/src/mib.cpp
>> @@ -668,8 +668,9 @@ int snmpRowStatus::unset()
>>                 value = undo;
>>                 undo = 0;
>>         }
>> +       return SNMP_ERROR_SUCCESS;
>>    }
>> -  return SNMP_ERROR_SUCCESS;
>> +  return SNMP_ERROR_UNDO_FAIL;
>>  }
>>    /**
>> 
>> Best regards
>> Claus
>> _______________________________________________
>> AGENTPP mailing list
>> AGENTPP at agentpp.org
>> https://oosnmp.net/mailman/listinfo/agentpp
> 
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