/// <summary>SNMP WALK operation</summary>
/// <remarks>
/// When using SNMP version 1, walk is performed using GET-NEXT calls. When using SNMP version 2,
/// walk is performed using GET-BULK calls.
/// </remarks>
/// <example>Example SNMP walk operation using SNMP version 1:
/// <code>
/// String snmpAgent = "10.10.10.1";
/// String snmpCommunity = "private";
/// SimpleSnmp snmp = new SimpleSnmp(snmpAgent, snmpCommunity);
/// Dictionary<Oid, AsnType> result = snmp.Walk(SnmpVersion.Ver1, "1.3.6.1.2.1.1");
/// if( result == null ) {
/// Console.WriteLine("Request failed.");
/// } else {
/// foreach (KeyValuePair<Oid, AsnType> entry in result)
/// {
/// Console.WriteLine("{0} = {1}: {2}", entry.Key.ToString(), SnmpConstants.GetTypeName(entry.Value.Type),
/// entry.Value.ToString());
/// }
/// </code>
/// Will return:
/// <code>
/// 1.3.6.1.2.1.1.1.0 = OctetString: "Dual core Intel notebook"
/// 1.3.6.1.2.1.1.2.0 = ObjectId: 1.3.6.1.9.233233.1.1
/// 1.3.6.1.2.1.1.3.0 = TimeTicks: 0d 0h 0m 1s 420ms
/// 1.3.6.1.2.1.1.4.0 = OctetString: "*****@*****.**"
/// 1.3.6.1.2.1.1.5.0 = OctetString: "milans-nbook"
/// 1.3.6.1.2.1.1.6.0 = OctetString: "Developer home"
/// 1.3.6.1.2.1.1.8.0 = TimeTicks: 0d 0h 0m 0s 10ms
/// </code>
///
/// To use SNMP version 2, change snmp.Set() method call first parameter to SnmpVersion.Ver2.
/// </example>
/// <param name="version">SNMP protocol version. Acceptable values are SnmpVersion.Ver1 and
/// SnmpVersion.Ver2</param>
/// <param name="rootOid">OID to start WALK operation from. Only child OIDs of the rootOid will be
/// retrieved and returned</param>
/// <returns>Oid => AsnType value mappings on success, empty dictionary if no data was found or
/// null on error</returns>
public Dictionary <Oid, AsnType> Walk(SnmpVersion version, string rootOid)
{
if (rootOid.Length < 2)
{
return(null);
}
Oid root = new Oid(rootOid);
if (root.Length <= 0)
{
return(null); // unable to parse root oid
}
Oid lastOid = (Oid)root.Clone();
Dictionary <Oid, AsnType> result = new Dictionary <Oid, AsnType>();
while (lastOid != null && root.IsRootOf(lastOid))
{
Dictionary <Oid, AsnType> val = null;
if (version == SnmpVersion.Ver1)
{
val = GetNext(version, new string[] { lastOid.ToString() });
}
else
{
val = GetBulk(new string[] { lastOid.ToString() });
}
// check that we have a result
if (val == null)
{
// error of some sort happened. abort...
return(null);
}
foreach (KeyValuePair <Oid, AsnType> entry in val)
{
if (root.IsRootOf(entry.Key))
{
result.Add(entry.Key, entry.Value);
lastOid = (Oid)entry.Key.Clone();
}
else
{
// it's faster to check if variable is null then checking IsRootOf
lastOid = null;
break;
}
}
}
return(result);
}
/// <summary>
/// Construct Vb with the supplied OID and Null value
/// </summary>
/// <param name="oid">OID</param>
public Vb(Oid oid)
: this()
{
_oid = (Oid)oid.Clone();
_value = new Null();
}
/// <summary>SNMP WALK operation</summary>
/// <remarks>
/// When using SNMP version 1, walk is performed using GET-NEXT calls. When using SNMP version 2,
/// walk is performed using GET-BULK calls.
/// </remarks>
/// <example>Example SNMP walk operation using SNMP version 1:
/// <code>
/// String snmpAgent = "10.10.10.1";
/// String snmpCommunity = "private";
/// SimpleSnmp snmp = new SimpleSnmp(snmpAgent, snmpCommunity);
/// Dictionary<Oid, AsnType> result = snmp.Walk(SnmpVersion.Ver1, "1.3.6.1.2.1.1");
/// if( result == null ) {
/// Console.WriteLine("Request failed.");
/// } else {
/// foreach (KeyValuePair<Oid, AsnType> entry in result)
/// {
/// Console.WriteLine("{0} = {1}: {2}", entry.Key.ToString(), SnmpConstants.GetTypeName(entry.Value.Type),
/// entry.Value.ToString());
/// }
/// </code>
/// Will return:
/// <code>
/// 1.3.6.1.2.1.1.1.0 = OctetString: "Dual core Intel notebook"
/// 1.3.6.1.2.1.1.2.0 = ObjectId: 1.3.6.1.9.233233.1.1
/// 1.3.6.1.2.1.1.3.0 = TimeTicks: 0d 0h 0m 1s 420ms
/// 1.3.6.1.2.1.1.4.0 = OctetString: "*****@*****.**"
/// 1.3.6.1.2.1.1.5.0 = OctetString: "milans-nbook"
/// 1.3.6.1.2.1.1.6.0 = OctetString: "Developer home"
/// 1.3.6.1.2.1.1.8.0 = TimeTicks: 0d 0h 0m 0s 10ms
/// </code>
///
/// To use SNMP version 2, change snmp.Set() method call first parameter to SnmpVersion.Ver2.
/// </example>
/// <param name="version">SNMP protocol version. Acceptable values are SnmpVersion.Ver1 and
/// SnmpVersion.Ver2</param>
/// <param name="rootOid">OID to start WALK operation from. Only child OIDs of the rootOid will be
/// retrieved and returned</param>
/// <returns>Oid => AsnType value mappings on success, empty dictionary if no data was found or
/// null on error</returns>
public Dictionary <Oid, AsnType> Walk(SnmpVersion version, string rootOid)
{
if (!Valid)
{
if (!_suppressExceptions)
{
throw new SnmpException("SimpleSnmp class is not valid.");
}
return(null);
}
// function only works on SNMP version 1 and SNMP version 2 requests
if (version != SnmpVersion.Ver1 && version != SnmpVersion.Ver2)
{
if (!_suppressExceptions)
{
throw new SnmpInvalidVersionException("SimpleSnmp support SNMP version 1 and 2 only.");
}
return(null);
}
if (rootOid.Length < 2)
{
if (!_suppressExceptions)
{
throw new SnmpException(SnmpException.InvalidOid, "RootOid is not a valid Oid");
}
return(null);
}
Oid root = new Oid(rootOid);
if (root.Length <= 0)
{
return(null); // unable to parse root oid
}
Oid lastOid = (Oid)root.Clone();
Dictionary <Oid, AsnType> result = new Dictionary <Oid, AsnType>();
while (lastOid != null && root.IsRootOf(lastOid))
{
Dictionary <Oid, AsnType> val = null;
if (version == SnmpVersion.Ver1)
{
val = GetNext(version, new string[] { lastOid.ToString() });
}
else
{
val = GetBulk(new string[] { lastOid.ToString() });
}
// check that we have a result
if (val == null)
{
// error of some sort happened. abort...
return(null);
}
foreach (KeyValuePair <Oid, AsnType> entry in val)
{
if (root.IsRootOf(entry.Key))
{
if (result.ContainsKey(entry.Key))
{
if (result[entry.Key].Type != entry.Value.Type)
{
throw new SnmpException(SnmpException.OidValueTypeChanged, "OID value type changed for OID: " + entry.Key.ToString());
}
else
{
result[entry.Key] = entry.Value;
}
}
else
{
result.Add(entry.Key, entry.Value);
}
lastOid = (Oid)entry.Key.Clone();
}
else
{
// it's faster to check if variable is null then checking IsRootOf
lastOid = null;
break;
}
}
}
return(result);
}
/// <summary>Construct Vb with the supplied OID and Null value</summary>
/// <param name="oid">OID</param>
public Vb(Oid oid)
: this()
{
this.oid = (Oid)oid.Clone();
value = new Null();
}
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);
}
private static bool WalkGetNext(IPAddress agent, string community, string oid, Func <Vb, bool> handleValue)
{
// SNMP community name
OctetString communityString = new OctetString(community);
// Define agent parameters class
AgentParameters param = new AgentParameters(communityString)
{
// Set SNMP version to 1
Version = SnmpVersion.Ver1
};
// 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.GetNext);
// Loop through results
while (lastOid != null)
{
// When Pdu class is first constructed, RequestId is set to a random value
// that needs to be incremented on subsequent requests made using the
// same instance of the Pdu class.
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
SnmpV1Packet result = (SnmpV1Packet)target.Request(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);
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);
}
