Cannot send/response for a snmpSet request with mutiple OIDs and their corresponding values

SNMP++/AGENT++
1

Hi,

I’m using Agent+±4.6.1 and SNMP+±3.5.1. Is it possiple to send a snmpSet request (using SNMP+±3.5.1) with multiple OIDs and their corresponding values in a single UDP message AND response this snmpSet request (using Agent+±4.6.1)?

It seems like we can send snmpGet request with multiple OIDs and send snmpSet with only 1 OID.
$ ./snmpGet --help
snmpGet IpAddress | DNSName [Oid [Oid…]] [options]
$ ./snmpSet --help
snmpSet IpAddress | DNSName [Oid] [options]

In AGENT++\src\mib.cpp (Mib::do_process_request(Request* req)), AGENT can process multiple subrequest for snmpGet request
int n = req->subrequests();
for (i=0; i<n; i++) {
if (!req->is_done(i))
if (!process_request(req, i)) break;

However, in Mib::process_set_request(Request* req), I did not see any function/method to process multiple OIDs. Are there other ways for agent++ to process and response to snmpSet several OIDs with new values in 1 request?
case (sNMP_PDU_SET): {
process_set_request(req);
int n = req->subrequests();
for (int j=0; j<n; j++)
LOG(req->get_oid(j).get_printable());

Thanks,
Phuoc

2

Yes, of course you can set multiple variables in a single SET PDU with SNMP++ and AGENT++ from the very first version.on.

I do not know why you think it would not work?
The code snippet you posted is for any PDU type regardless of SET or GET!

3

The snmpGet request could send multiple OIDs and Agent could response fine
$ ./snmpGet --help
snmpGet IpAddress | DNSName [Oid [Oid…]] [options]
$ ./snmpGet 127.0.0.1 1.3.6.1.4.1.4976.6.3.1.1.0 1.3.6.1.4.1.4976.6.2.1.1.0 -P4700 -v3 -snusr-sha-aes -authSHA -privAES128 -uakey1 -upkey1
VB nr: 0
Oid = 1.3.6.1.4.1.4976.6.3.1.1.0
Value = 0
Syntax = 66

VB nr: 1
Oid = 1.3.6.1.4.1.4976.6.2.1.1.0
Value = 0
Syntax = 2

However, The snmpSet request could send multiple OIDs
$ ./snmpSet --help
snmpSet IpAddress | DNSName [Oid] [options]
$ ./snmpSet 127.0.0.1 1.3.6.1.4.1.4976.6.3.1.1.0 1.3.6.1.4.1.4976.6.2.1.1.0 -P4700 -v3 -snusr-sha-aes -authSHA -privAES128 -uakey1 -upkey1
Error: unknown parameter: 1.3.6.1.4.1.4976.6.2.1.1.0
Usage:
snmpSet IpAddress | DNSName [Oid] [options]

Also in Mib::process_set_request(Request* req), I did not see any function/method to process multiple OIDs. There is no request index for subrequest.

case (sNMP_PDU_SET): {
process_set_request(req);
break;
}
void Mib::process_set_request(Request* req)
{
int n = req->subrequests();

LOG_BEGIN(loggerModuleName, EVENT_LOG | 2);
LOG("Mib: process request: set request (tid)(oid)");
LOG(req->get_transaction_id());

for (int j=0; j<n; j++)
	LOG(req->get_oid(j).get_printable());
LOG_END;
req->phase++; // indicate PHASE_PREPARE
if (process_prepare_set_request(req) == SNMP_ERROR_SUCCESS) {
	req->phase++; // indicate PHASE_COMMIT
	if (process_commit_set_request(req) !=
	    SNMP_ERROR_SUCCESS) {

		req->phase++;

		LOG_BEGIN(loggerModuleName, WARNING_LOG | 2);
		LOG("Mib: commit failed (tid)");
		LOG(req->get_transaction_id());
		LOG_END;

		process_undo_set_request(req);
		return;
	}
}
req->phase = PHASE_CLEANUP;
process_cleanup_set_request(req);

}

4

You can make use of the PDU’s set_vblist(Vb const *, const int) method to pass multiple OIDS in a single request. This is assumed that the Agent that you are communicating with has been programed to sufficiently respond with vbLists.

Here’s a basic code example that could get you in the right direction.


std::vector<Snmp_pp:Vb> vbList;
Snmp_pp::Vb vb1;
Snmp_pp::Vb vb2;
vb1.set_oid("1.3.6.1.4.1...1.0");
vb2.set_oid("1.3.6.1.4.1...2.0");

unsigned int value1 = 1;
unsigned int value2 = 2;

vb1.set_value(value1);
vb2.set_value(value2);

vbList.pushback(vb1);
vbList.pushback(vb2);

Snmp_pp::Pdu pdu;
int status;
//If ivp6 use true as the constructor's argument
Snmp_pp::Snmp snmp(status, 0, false);
pdu.set_vblist(&vbList[0], static_cast<int>(vbList.size()));

Snmp_pp::UTarget utarget = target;
status = snmp.set(pdu, target);

if(status != SNMP_CLASS_SUCCESS)
{
	std::cout <<"Error: " << snmp.error_msg(status);
}
5

Hi Steven,

Thanks for your info.

Frank said we can set multiple variables in a single SET PDU with SNMP++ and AGENT++ from the very first version. I’m trying to figure out what is going on with Agent+±4.6.1 and SNMP+±3.5.1.

6

The snmpSet command sample tool is only a sample and does not implement all features the SNMP++ API has.