Integer value parsed incorrectly in some cases

[burmisov]

Hi! Thanks for an awesome module!

I have a problem with a rather exotic device trying to read a temperature sensor value.
The code is simple:

var snmp = require('net-snmp');
var session = snmp.createSession('10.157.207.28', 'public', { version: snmp.Version1 });
session.get(['1.3.6.1.4.1.40418.2.4.4.1.0'], function (error, varbinds) {
    if (error) {
        throw error;
    }
    console.log('result>', varbinds);
    session.close();
});

What I get is an Integer too long (129) error. I drilled it down to the source and it looks like at this point an extra byte with value 129 is getting in the way for some reason. If I discard it prior to processing (i.e., add another buffer.readByte (); after this line, the value is parsed correctly. But I guess that'a a pretty bad hack.

I thought maybe the device is causing problems (I can read multiple other devices without issues), but both snmpget cli utility and the Free SNMP MIB Browser of ManageEngine seem to handle this OID of my device without any issues.

Maybe I will get down to the problem myself eventually, but some couple hours spent to this moment didn't bring me a solution.

[stephenwvickers]

Hi Sergey,

Sorry for the delay in my response.

This would suggest an issue with the structure of the response packet.

Are you able to send me a Wireshark capture which includes the SNMP response packet (or similar)?

Thanks

Steve

[burmisov]

Hi Stephen!
No worries, my fork with a hack that checks for the 129 value surprisingly works for all of the devices I have at hand :)
I guess there may be wrong structure in the response, and I never would create and issue here but for snpmget getting a good result.
I'll create a capture ASAP, wen I get my hands on the device again.

[stephenwvickers]

That's ok, I understand.

If there is an issue there I would like to address it for you.

Thanks

Steve

[stephenwvickers]

If you would like to look into this further just reopen the issue and I will continue to investigate.

Thanks

Steve

[markabrahams]

This is long closed, but @burmisov if you're still out there, and you still care, this issue is fixed in version 2.9.8 of the npm. See #136 for further details of the problem and fix.