Using addOIDHandler()

[majidhamaoui]

Hello,
In order to use addOIDHandler() to read OID type, I had few issues that I resolved by:
1- In parsePackey() case OID: replace

strncpy(((OIDCallback *)callback)->value, oidStr, 64 - 1); 
((OIDCallback *)callback)->value[64 - 1] = '\0';

by

strncpy(((OIDCallback *)callback)->value, oidValue->_value, strlen(oidValue->_value));
((OIDCallback *)callback)->value[strlen(oidValue->_value)] = '\0';

2- In ValueCallback *SNMPManager::addOIDHandler(IPAddress ip, const char *oid, char *value):
addstrcpy(callback->OID, oid);

[shortbloke]

Hi, Are you able to share more about the problem you experienced and why this code change fixed it?

I've not worked on this project for a while, but your change looks to change response from containing the OID string, to containing the value associated with that in the payload.

If you can expand I can see if I get a better grasp of the issue.

[majidhamaoui]

Hi,
before adding the line: strcpy(callback->OID, oid); the system was crashing (Stack smashing protect failure) and just after adding it, I received wrong value when asking for an OID response, then I modified the first lines.

[shortbloke]

Are you able to test a variation of your change for me?

In addOIDHandler()

// Store the OID in the callback safely
strncpy(callback->OID, oid, sizeof(callback->OID) - 1);
callback->OID[sizeof(callback->OID) - 1] = '\0';

In parsePacket()

// Store the returned SNMP value in the callback safely
strncpy(((OIDCallback *)callback)->value,
        oidValue->_value,
        sizeof(((OIDCallback *)callback)->value) - 1);

((OIDCallback *)callback)->value[sizeof(((OIDCallback *)callback)->value) - 1] = '\0';