Only able to get SysUpTime OID to work

[dmarc1234]

Hello.

I am trying to use your library to create a simple SNMP system on my ESP32 board but can only get the SysUpTime OID working.

I have added the following lines to your example:

static unsigned char sysContact[] = {0x2b, 0x06, 0x01, 0x02, 0x01, 0x01, 0x04, 0x00};
char contact[16] = "system contact";
kedi.addObject(sysContact, 8, STRING, &contact);

but when I access OID .1.3.6.1.2.1.1.3.0 (sysContact) I get nothing returned in iReasoning MIB browser but no error. Does the STRING GET function not work in this library as I get 'Type Sequence of length 25 and has 0 children' with a type 'Sequence' on any request I make although the sysUpTime OID does also say 'Type Sequence of length 16 and has 0 children' so I am confused why that works ?

Any help would be welcome as I cannot get it to work.

[semihiseri]

Hi,Can you describe your setup a bit more so I can try to recreate it? Some schematics/block diagrams would be excellent. I initially made this software/library for a client to run on arduino mega, and then neglected it. So I never tested it on ESP32 myself. But I can definitely see the utility with ESP32s since they can handle the processing needs and they have the connectivity out of the box!Best,Semih. On 31. Jan 2023, at 12.19, dmarc1234 ***@***.***> wrote: Hello. I am trying to use your library to create a simple SNMP system on my ESP32 board but can only get the SysUpTime OID working. I have added the following lines to your example: static unsigned char sysContact[] = {0x2b, 0x06, 0x01, 0x02, 0x01, 0x01, 0x04, 0x00}; char contact[16] = "system contact"; kedi.addObject(sysContact, 8, STRING, &contact); but when I access OID .1.3.6.1.2.1.1.3.0 (sysContact) I get nothing returned in iReasoning MIB browser but no error. Does the STRING GET function not work in this library as I get 'Type Sequence of length 25 and has 0 children' with a type 'Sequence' on any request I make although the sysUpTime OID does also say 'Type Sequence of length 16 and has 0 children' so I am confused why that works ? Any help would be welcome as I cannot get it to work. —Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[dmarc1234]

To provide a bit more information I have looked at the log in iReasoning it shows the following for the sysContact response:

2023-01-31 10:51:27,728 DEBUG [Thread-25] - 30 36 02 01 01 04 06 70 75 62 6C 69 63 A2 29 02 06.....public.).
2023-01-31 10:51:27,728 DEBUG [Thread-25] - 04 03 2E 61 E9 02 01 00 02 01 00 30 1B 30 19 06 ...a.......0.0..
2023-01-31 10:51:27,728 DEBUG [Thread-25] - 08 2B 06 01 02 01 01 04 00 13 0E 73 79 73 74 65 .+.........syste
2023-01-31 10:51:27,728 DEBUG [Thread-25] - 6D 20 63 6F 6E 74 61 63 m contac
2023-01-31 10:51:27,728 WARN [Thread-25] - Couldn't decode all variable bindings. PDU.requestID:53371369

So it looks like there is a response but there is a decode error,

[dmarc1234]

Hi @semihiseri and thank you for your response.

Great little library that I am hoping to use with SNMPv3 but would like to get the core functionality working first.

It looks like the value Type designator is incorrect just before the string is returned, is 0x0E right ?

[dmarc1234]

Hi @semihiseri did you manage to have a look at this problem.

Still looks to me to be an incorrect Type designator just before the string is returned and the string is not being fully sent, the last 't' is missing.
Probably a small change but without digging into your library code I would not know where to start.

Looking forward to your reply.

[dmarc1234]

I have managed to correct the library so that it now reports STRING type OIDs correctly and have also made some mods that allow INT8, INT16 and bool values to be returned as well.

One thing I did want to support is tables and wondered if you had given any thought to how this might be done in the currently library ?

Library works great on the ESP32 and SNMP is fast and responsive so thank you for your work so far.

[dmarc1234]

Hi @semihiseri just wondered if you had seen the comments above.

I have manged to implement SET in the library for SNMPv2 and am now working on v2 traps.

I am going to need a little help with this please as I cannot understand how you add additional varibinds to the trap.

I see that you are loading a trap template and then adding the first varibind to children[0] and then the trap OID to children[1] as the final varibind. This works fine for just the single varibind but I have tried to add additional varibinds before the first using iterations of this code:

    dummy = this->message.variableBindings;
    dummy = &(dummy->children[0]);
    oidNo = this->findOID(oid, len);
    x = objects[oidNo].returnObject(temp);
    dummy->_length = x;
    dummy->_content = temp;
    dummy->printSelf();
    dummy->printContent();

using dummy->children[n] as above but it messes up the final trap format.

Your help would be greatly appreciated.

[Bastigst]

@dmarc1234 Hi,

can you tell me what you've changed in the code?

So i can send Strings?

Thanks :)