| public RequestAsync ( Pdu pdu, IAgentParameters agentParameters, SnmpAsyncResponse responseCallback ) : bool | ||
| pdu | Pdu | Pdu class (do not pass ScopedPdu) |
| agentParameters | IAgentParameters | Security information for the request. Use |
| responseCallback | SnmpAsyncResponse | Callback that receives the result of the async operation. |
| return | bool | |
public async static Task <bool> SetAsync(IPAddress agent, string community, string oid, int value, Func <Oid, string, bool> handleValue)
{
// Prepare target
UdpTarget target = new UdpTarget(agent);
// Create a SET PDU
Pdu pdu = new Pdu(PduType.Set);
var oidValue = new Oid(oid);
// Set a value to integer
pdu.VbList.Add(oidValue, new Integer32(value));
// Set Agent security parameters
AgentParameters aparam = new AgentParameters(SnmpVersion.Ver2, new OctetString(community));
// Response packet
SnmpV2Packet response;
try
{
// Send request and wait for response
response = await target.RequestAsync(pdu, aparam) as SnmpV2Packet;
}
catch (Exception)
{
// If exception happens, it will be returned here
//System.Diagnostics.Debug.WriteLine(String.Format("Request failed with exception: {0}", ex.Message));
target.Close();
return(false);
}
// Make sure we received a response
if (response == null)
{
//System.Diagnostics.Debug.WriteLine("Error in sending SNMP request.");
}
else
{
// Check if we received an SNMP error from the agent
if (response.Pdu.ErrorStatus != 0)
{
//System.Diagnostics.Debug.WriteLine(String.Format("SNMP agent returned ErrorStatus {0} on index {1}",
// response.Pdu.ErrorStatus, response.Pdu.ErrorIndex));
}
else
{
// Everything is ok. Agent will return the new value for the OID we changed
//System.Diagnostics.Debug.WriteLine(String.Format("Agent response {0}: {1}",
// response.Pdu[0].Oid.ToString(), response.Pdu[0].Value.ToString()));
handleValue(oidValue, response.Pdu[0].Value.ToString());
}
}
return(true);
}
public async static Task <AsnType> GetAsync(IPAddress agent, string community, string oid)
{
// Define agent parameters class
AgentParameters agentParameters = new AgentParameters(SnmpVersion.Ver2, new OctetString(community));
// Construct target
UdpTarget target = new UdpTarget(agent, 161, 2000, 1);
// Pdu class used for all requests
Pdu pdu = new Pdu(PduType.Get);
pdu.VbList.Add(oid); //sysDescr
// Make SNMP request
var snmpResponse = await target.RequestAsync(pdu, agentParameters) as SnmpV2Packet;
AsnType result = null;
// If result is null then agent didn't reply or we couldn't parse the reply.
if (snmpResponse != null)
{
// ErrorStatus other then 0 is an error returned by
// the Agent - see SnmpConstants for error definitions
if (snmpResponse.Pdu.ErrorStatus != 0)
{
// agent reported an error with the request
throw new Exception($"Error in SNMP reply. Error {snmpResponse.Pdu.ErrorStatus} index {snmpResponse.Pdu.ErrorIndex}");
}
else
{
result = snmpResponse.Pdu.VbList[0].Value;
}
}
target.Close();
return(result);
}
private static async Task <bool> WalkGetBulkAsync(IPAddress agent, string community, string oid, Func <Vb, bool> handleValue)
{
OctetString communityString = new OctetString(community);
// Define agent parameters class
AgentParameters param = new AgentParameters(communityString);
// Set SNMP version to 2 (GET-BULK only works with SNMP ver 2 and 3)
param.Version = SnmpVersion.Ver2;
// Construct target
UdpTarget target = new UdpTarget(agent, 161, 2000, 1);
// Define Oid that is the root of the MIB
// tree you wish to retrieve
Oid rootOid = new Oid(oid); // ifDescr
// This Oid represents last Oid returned by
// the SNMP agent
Oid lastOid = (Oid)rootOid.Clone();
// Pdu class used for all requests
Pdu pdu = new Pdu(PduType.GetBulk)
{
// In this example, set NonRepeaters value to 0
NonRepeaters = 0,
// MaxRepetitions tells the agent how many Oid/Value pairs to return
// in the response.
MaxRepetitions = 5
};
// Loop through results
while (lastOid != null)
{
// When Pdu class is first constructed, RequestId is set to 0
// and during encoding id will be set to the random value
// for subsequent requests, id will be set to a value that
// needs to be incremented to have unique request ids for each
// packet
if (pdu.RequestId != 0)
{
pdu.RequestId += 1;
}
// Clear Oids from the Pdu class.
pdu.VbList.Clear();
// Initialize request PDU with the last retrieved Oid
pdu.VbList.Add(lastOid);
// Make SNMP request
//var result = (SnmpV1Packet)target.Request(pdu, param);
SnmpV2Packet result = (SnmpV2Packet)(await target.RequestAsync(pdu, param));
// You should catch exceptions in the Request if using in real application.
// If result is null then agent didn't reply or we couldn't parse the reply.
if (result != null)
{
// ErrorStatus other then 0 is an error returned by
// the Agent - see SnmpConstants for error definitions
if (result.Pdu.ErrorStatus != 0)
{
// agent reported an error with the request
//System.Diagnostics.Debug.WriteLine("Error in SNMP reply. Error {0} index {1}",
// result.Pdu.ErrorStatus,
// result.Pdu.ErrorIndex);
lastOid = null;
break;
}
else
{
// Walk through returned variable bindings
foreach (Vb v in result.Pdu.VbList)
{
// Check that retrieved Oid is "child" of the root OID
if (rootOid.IsRootOf(v.Oid))
{
//System.Diagnostics.Debug.WriteLine("{0} ({1}): {2}",
// v.Oid.ToString(),
// SnmpConstants.GetTypeName(v.Value.Type),
// v.Value.ToString());
handleValue(v);
if (v.Value.Type == SnmpConstants.SMI_ENDOFMIBVIEW)
{
lastOid = null;
}
else
{
lastOid = v.Oid;
}
}
else
{
// we have reached the end of the requested
// MIB tree. Set lastOid to null and exit loop
lastOid = null;
}
}
}
}
else
{
//System.Diagnostics.Debug.WriteLine("No response received from SNMP agent.");
}
}
target.Close();
return(true);
}
