SNMPTCPAgent Class

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The SNMPTCPAgent class is used to implement TCP-based SNMP Agent Applications.

Syntax

ipworkssnmp.SNMPTCPAgent

Remarks

The SNMPTCPAgent class implements a TCP-based standard SNMP Agent as specified in the SNMP RFCs. The class supports SNMP v1, v2c, and v3.

The class provides both encoding/decoding and transport capabilities, making the task of developing a custom SNMP agent as simple as setting a few key properties and handling a few events. SNMP data such as SNMP object id-s (OID-s) are exchanged as text strings, thus further simplifying the task of handling them.

The class is activated/deactivated by calling the Activate or Deactivate method. These methods enable or disable sending and receiving. The activation status can be found in the Active property.

The class operates asynchronously. Requests are received through events such as GetRequest, GetBulkRequest, GetNextRequest, etc. and the corresponding responses are automatically sent when the events return. Traps are sent through the SendTrap method.

SNMPv3 USM security passwords are requested through the GetUserPassword event, and event parameters such as User and SecurityLevel provide information about the security attributes of received requests, and enable granular decision capability about what to provide and what not to provide. The SendSecureTrap method is used to send authenticated (secure) SNMPv3 traps.

The AddUser, RemoveUser, ShowCache, and ClearCache methods are used to manage an internal authentication cache. This internal cache can be used as an alternative to the GetUserPassword event, automatically checking the cache against the security parameters provided in the request signature.

SNMP OIDs, types, and values are provided in the Objects collection of SNMP objects for both sent and received packets.

Other packet information is provided through corresponding event parameters, such as Community, or RequestId.

Property List

The following is the full list of the properties of the class with short descriptions. Click on the links for further details.

Method List

The following is the full list of the methods of the class with short descriptions. Click on the links for further details.

Event List

The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.

Config Settings

The following is a list of config settings for the class with short descriptions. Click on the links for further details.

AcceptData Property (SNMPTCPAgent Class)

Enables or disables data reception.

Syntax

public boolean isAcceptData();
public void setAcceptData(boolean acceptData);

Default Value

True

Remarks

Setting the property to False temporarily disables data reception. Setting the property to True re-enables data reception.

This property is not available at design time.

Active Property (SNMPTCPAgent Class)

Indicates whether the class is active.

Syntax

public boolean isActive();
public void setActive(boolean active);

Default Value

False

Remarks

This property indicates whether the class is currently active and can send or receive data.

The class will be automatically activated if it is not already and you attempt to perform an operation which requires the class to be active.

Use the Activate and Deactivate methods to control whether the class is active.

This property is not available at design time.

LocalEngineId Property (SNMPTCPAgent Class)

The Engine Id of the SNMP Agent.

Syntax

public byte[] getLocalEngineId();
public void setLocalEngineId(byte[] localEngineId);

Default Value

""

Remarks

This property is only used for SNMPv3 packets (when SNMPVersion is 3).

LocalHost Property (SNMPTCPAgent Class)

The name of the local host or user-assigned IP interface through which connections are initiated or accepted.

Syntax

public String getLocalHost();
public void setLocalHost(String localHost);

Default Value

""

Remarks

This property contains the name of the local host as obtained by the gethostname() system call, or if the user has assigned an IP address, the value of that address.

In multihomed hosts (machines with more than one IP interface) setting LocalHost to the IP address of an interface will make the class initiate connections (or accept in the case of server classs) only through that interface. It is recommended to provide an IP address rather than a hostname when setting this property to ensure the desired interface is used.

If the class is connected, the LocalHost property shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multihomed hosts (machines with more than one IP interface).

Note: LocalHost is not persistent. You must always set it in code, and never in the property window.

LocalPort Property (SNMPTCPAgent Class)

The port in the local host where the class listens.

Syntax

public int getLocalPort();
public void setLocalPort(int localPort);

Default Value

161

Remarks

The LocalPort property must be set before the class is activated (Active is set to True). It instructs the class to bind to a specific port (or communication endpoint) in the local machine (default 161).

You may also set LocalPort to 0. This allows the TCP/IP stack to choose a port at random. The value chosen is provided via the LocalPort property after the class is activated through the Active property.

LocalPort cannot be changed once the class is Active. Any attempt to set the LocalPort property when the class is Active will generate an error.

Note: on macOS and iOS, root permissions are required to set LocalPort to any value below 1024.

Objects Property (SNMPTCPAgent Class)

The objects in the current request.

Syntax

public SNMPObjectList getObjects();
public void setObjects(SNMPObjectList objects);

Remarks

The SNMP objects being sent or received in the current request. The collection is first cleared, then populated every time an SNMP packet is received. It is also used to create outgoing SNMP packets.

This collection is indexed from 0 to size -1.

RequestId Property (SNMPTCPAgent Class)

The request-id to mark outgoing packets with.

Syntax

public int getRequestId();
public void setRequestId(int requestId);

Default Value

1

Remarks

If a custom value is needed for RequestId, the property must be set before sending the request. The class increments RequestId automatically after sending each packet.

This property is not available at design time.

SNMPVersion Property (SNMPTCPAgent Class)

Version of SNMP used for outgoing requests (traps).

Syntax

public int getSNMPVersion();
public void setSNMPVersion(int SNMPVersion);

Enumerated values:
  public final static int snmpverV1 = 1;
  public final static int snmpverV2c = 2;
  public final static int snmpverV3 = 3;

Default Value

2

Remarks

This property takes one of the following values:

SSLAcceptServerCert Property (SNMPTCPAgent Class)

Instructs the class to unconditionally accept the server certificate that matches the supplied certificate.

Syntax

public Certificate getSSLAcceptServerCert();
public void setSSLAcceptServerCert(Certificate SSLAcceptServerCert);

Remarks

If it finds any issues with the certificate presented by the server, the class will normally terminate the connection with an error.

You may override this behavior by supplying a value for SSLAcceptServerCert. If the certificate supplied in SSLAcceptServerCert is the same as the certificate presented by the server, then the server certificate is accepted unconditionally, and the connection will continue normally.

Note: This functionality is provided only for cases in which you otherwise know that you are communicating with the right server. If used improperly, this property may create a security breach. Use it at your own risk.

SSLAuthenticateClients Property (SNMPTCPAgent Class)

If set to True, the server asks the client(s) for a certificate.

Syntax

public boolean isSSLAuthenticateClients();
public void setSSLAuthenticateClients(boolean SSLAuthenticateClients);

Default Value

False

Remarks

This property is used in conjunction with the SSLClientAuthentication event. Please refer to the documentation of the SSLClientAuthentication event for details.

SSLCert Property (SNMPTCPAgent Class)

The certificate to be used during Secure Sockets Layer (SSL) negotiation.

Syntax

public Certificate getSSLCert();
public void setSSLCert(Certificate SSLCert);

Remarks

This property includes the digital certificate that the class will use during SSL negotiation. Set this property to a valid certificate before starting SSL negotiation. To set a certificate, you may set the Encoded field to the encoded certificate. To select a certificate, use the store and subject fields.

SSLEnabled Property (SNMPTCPAgent Class)

Whether TLS/SSL is enabled.

Syntax

public boolean isSSLEnabled();
public void setSSLEnabled(boolean SSLEnabled);

Default Value

False

Remarks

This setting specifies whether TLS/SSL is enabled in the class. When False (default) the class operates in plaintext mode. When True TLS/SSL is enabled.

This property is not available at design time.

SSLServerCert Property (SNMPTCPAgent Class)

The server certificate for the last established connection.

Syntax

public Certificate getSSLServerCert();

Remarks

This property contains the server certificate for the last established connection.

SSLServerCert is reset every time a new connection is attempted.

This property is read-only.

SysUpTime Property (SNMPTCPAgent Class)

Time passed since the agent was initialized (in hundredths of a second).

Syntax

public long getSysUpTime();
public void setSysUpTime(long sysUpTime);

Default Value

0

Remarks

This property is used when sending SNMP traps, and it normally provides the time since the system was restarted in 1/100s of a second.

If another value is desired, you may set this property to a custom value. From that point on, SysUpTime will return the value set plus time elapsed.

This property is not available at design time.

Activate Method (SNMPTCPAgent Class)

Activates the class.

Syntax

public void activate();

Remarks

This method activates the component and will allow it to send or receive data.

The class will be automatically activated if it is not already and you attempt to perform an operation which requires the class to be active.

Note: Use the Active property to check whether the component is active.

AddUser Method (SNMPTCPAgent Class)

Adds a user to the internal authentication cache.

Syntax

public void addUser(String user, int authenticationProtocol, String authenticationPassword, int encryptionAlgorithm, String encryptionPassword);

Remarks

The internal authentication cache can be used as an alternative to the GetUserPassword event, automatically checking the cache against the security parameters provided in the request signature.

The ShowCache method is used to show the contents of the internal authentication cache.

The ClearCache method can be used to completely clear the cache.

Valid Authentication Protocols are:

Valid Encryption Algorithms are:

NOTE: Specifying an authentication protocol of 0 is a special case where the class will attempt to verify users with all valid authentication protocols.

ClearCache Method (SNMPTCPAgent Class)

Clears the internal authentication database.

Syntax

public void clearCache();

Remarks

All user records are removed from the internal authentication cache as a result of this call.

Config Method (SNMPTCPAgent Class)

Sets or retrieves a configuration setting.

Syntax

public String config(String configurationString);

Remarks

Config is a generic method available in every class. It is used to set and retrieve configuration settings for the class.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

Deactivate Method (SNMPTCPAgent Class)

Deactivates the class.

Syntax

public void deactivate();

Remarks

This method deactivates the component and will prohibit it from sending and receiving data.

Note: Use the Active property to check whether the component is active.

DoEvents Method (SNMPTCPAgent Class)

This method processes events from the internal message queue.

Syntax

public void doEvents();

Remarks

When DoEvents is called, the class processes any available events. If no events are available, it waits for a preset period of time, and then returns.

HashPasswords Method (SNMPTCPAgent Class)

Hashes all passwords in the cache.

Syntax

public void hashPasswords();

Remarks

Forces computation of all passwords hashes in the cache. Used together with the HashPassword event to enable implementations of external password hash storage.

RemoveUser Method (SNMPTCPAgent Class)

Removes the user specified by User from the internal authentication cache.

Syntax

public void removeUser(String user);

Remarks

The internal authentication cache can be used as an alternative to the GetUserPassword event, automatically checking the cache against the security parameters provided in the request signature.

The ShowCache method is used to show the contents of the internal authentication cache.

The ClearCache method can be used to completely clear the cache.

Reset Method (SNMPTCPAgent Class)

Clears the object arrays.

Syntax

public void reset();

Remarks

Clears the object arrays, and sets the trap and error properties to their default values. This is useful for reinitializing all the properties that are used to create outgoing packets before building a new packet.

Note: SNMPVersion will be reset to snmpverV2c (2).

SendResponse Method (SNMPTCPAgent Class)

Sends a response packet to a Get, Get-Next, Get-Bulk, or Set request.

Syntax

public void sendResponse(String remoteHost, int remotePort, int requestId, String community, int errorStatus, int errorIndex);

Remarks

Use this method to send asynchronous response packets. A valid RequestId must be specified. SendResponse sends an unauthenticated response packet. Depending upon the value of the SNMPVersion property, the packet is constructed as an SNMPv1, SNMPv2c, or SNMPv3 (unauthenticated) response PDU. To send authenticated or encrypted SNMPv3 responses, use SendSecureResponse

The RemoteHost and RemotePort parameters are used to determine where the response is to be sent. The object identifiers, types, and values for the request are taken from the Objects collection. The RequestId, Community, ErrorStatus, and ErrorIndex parameters are used to specify other properties of the response.

SendSecureResponse Method (SNMPTCPAgent Class)

Sends an authenticated and/or encrypted SNMPv3 response.

Syntax

public void sendSecureResponse(String remoteHost, int remotePort, int requestId, int messageId, int errorStatus, int errorIndex, String user, int authenticationProtocol, String authenticationPassword, int encryptionAlgorithm, String encryptionPassword);

Remarks

Similar to the SendResponse method except that User, Authentication Protocol, and AuthenticationPassword are used to authenticate the response. EncryptionAlgorithm and EncryptionPassword (if not empty) are used to encrypt the response.

The MessageId argument must match the MessageId parameter obtained from the GetRequest, GetNextRequest, SetRequest, or GetBulkRequest event.

The user and password arguments used to send the response will be added to the internal user cache. If the user is already in the cache, its passwords will be updated with those supplied.

Valid Authentication Protocols are:

Valid Encryption Algorithms are:

SendSecureTrap Method (SNMPTCPAgent Class)

Sends an authenticated and/or encrypted SNMPv3 trap.

Syntax

public void sendSecureTrap(String remoteHost, String trapOID, String user, int authenticationProtocol, String authenticationPassword, int encryptionAlgorithm, String encryptionPassword);

Remarks

Similar to the SendTrap method except that User, AuthenticationPassword, and Authentication Protocol are used to authenticate the trap. EncryptionPassword (if not empty) and EncryptionAlgorithm are used to encrypt the message.

The user and password arguments used to send the trap will be added to the internal user cache. If the user is already in the cache, its passwords will be updated with those supplied.

Valid Authentication Protocols are:

Valid Encryption Algorithms are:

SendTrap Method (SNMPTCPAgent Class)

Sends an SNMP Trap.

Syntax

public void sendTrap(String remoteHost, String trapOID);

Remarks

Depending upon the value of the SNMPVersion property, the packet is constructed as an SNMPv1 or SNMPv2 Trap PDU. The following configuration settings provide more control about how traps are generated: TrapPort, TrapAgentAddress, TrapCommunity, TrapEnterprise. The SysUpTime property provides the trap timestamp.

SendTrap sends an unauthenticated trap. The SendSecureTrap method is used to send authenticated SNMPv3 traps.

If any values are provided in the Objects collection, they are sent unchanged. In the case of an SNMPv2 or SNMPv3 Trap, if Objects has a count that is equal to 0, the following values are set: sysUpTime.0 equal to SysUpTime and snmpTrapOID.0 equal to TrapOID.

For SNMPv2 and SNMPv3 Traps, TrapOID must contain the full OID of the Trap. For SNMPv1, TrapOID must be a string of the form "generic.specific" where generic and specific are numeric values providing the Trap Generic Type and Specific Type.

For SNMPv1, TrapOID must be of the form "GenericTrap.SpecificTrap". These values are sent in the PDU header. TrapAgentAddress and TrapEnterprise are taken from the corresponding configuration settings.

Additionally, the following symbolic values are recognized and translated as follows:

ShowCache Method (SNMPTCPAgent Class)

Lists all entries in the internal user authentication cache.

Syntax

public void showCache();

Remarks

A CacheEntry event is fired for every record in the internal user authentication cache.

The internal authentication cache can be used as an alternative to the GetUserPassword event, automatically checking the cache against the security parameters provided in the request signature.

The ShowCache method is used to show the contents of the internal authentication cache.

The ClearCache method can be used to completely clear the cache.

Value Method (SNMPTCPAgent Class)

Returns the value corresponding to an OID.

Syntax

public String value(String OID);

Remarks

If the OID does not exist in the Objects collection, a trappable error is generated.

Please refer to the SNMPObject type for more information.

BadPacket Event (SNMPTCPAgent Class)

Fired for erroneous and/or malformed messages.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void badPacket(SNMPTCPAgentBadPacketEvent e) {}
  ...
}

public class SNMPTCPAgentBadPacketEvent {
  public byte[] packet;
  public String sourceAddress;
  public int sourcePort;
  public int errorCode;
  public String errorDescription;
  public boolean report; //read-write
}

Remarks

The full message is provided in the Packet parameter.

The BadPacket event is also fired when authentication fails for received packets due to a bad password or other reasons.

If the Report parameter is set to True, an unauthenticated error report will be sent to the client, otherwise the packet will be silently ignored.

Please refer to the GetUserPassword event for more information concerning SNMPv3 authentication.

CacheEntry Event (SNMPTCPAgent Class)

Shows in the internal cache.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void cacheEntry(SNMPTCPAgentCacheEntryEvent e) {}
  ...
}

public class SNMPTCPAgentCacheEntryEvent {
  public String user;
  public String authenticationProtocol;
  public String authenticationPassword;
  public String encryptionAlgorithm;
  public String encryptionPassword;
}

Remarks

CacheEntry events are triggered by a call to ShowCache. One event is fired for each user.

Connected Event (SNMPTCPAgent Class)

Fired immediately after a connection completes (or fails).

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void connected(SNMPTCPAgentConnectedEvent e) {}
  ...
}

public class SNMPTCPAgentConnectedEvent {
  public String remoteAddress;
  public int remotePort;
  public int statusCode;
  public String description;
}

Remarks

This event fires after a connection completes or fails.

StatusCode is the value returned by the system TCP/IP stack. This will be 0 if the connection was successful.

Description contains a human readable description of the status. This will be "OK" if the connection was successful.

RemoteAddress is the IP address of the remote host.

RemotePort is the port on the remote host.

ConnectionStatus Event (SNMPTCPAgent Class)

This event is fired to indicate changes in the connection state.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void connectionStatus(SNMPTCPAgentConnectionStatusEvent e) {}
  ...
}

public class SNMPTCPAgentConnectionStatusEvent {
  public String connectionEvent;
  public int statusCode;
  public String description;
}

Remarks

The ConnectionStatus event is fired when the connection state changes: for example, completion of a firewall or proxy connection or completion of a security handshake.

The ConnectionEvent parameter indicates the type of connection event. Values may include the following:

Description contains a description of this code. The value of StatusCode is equal to the value of the error.

Disconnected Event (SNMPTCPAgent Class)

Fired when a connection is closed.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void disconnected(SNMPTCPAgentDisconnectedEvent e) {}
  ...
}

public class SNMPTCPAgentDisconnectedEvent {
  public String remoteAddress;
  public int remotePort;
  public int statusCode;
  public String description;
}

Remarks

This event fires after a connection is broken.

StatusCode is the value returned by the system TCP/IP stack. This will be 0 if the connection was broken normally.

Description contains a human readable description of the status. This will be "OK" if the connection was broken normally.

RemoteAddress is the IP address of the remote host.

RemotePort is the port on the remote host.

DiscoveryRequest Event (SNMPTCPAgent Class)

Fired when an SNMPv3 discovery packet is received.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void discoveryRequest(SNMPTCPAgentDiscoveryRequestEvent e) {}
  ...
}

public class SNMPTCPAgentDiscoveryRequestEvent {
  public byte[] engineId;
  public int engineBoots;
  public int engineTime;
  public String user;
  public int securityLevel;
  public String sourceAddress;
  public int sourcePort;
  public boolean respond; //read-write
}

Remarks

EngineId, EngineBoots, EngineTime, and User are the values received from SourceAddress.

For SNMPv3, the User parameter shows the user that was supplied with the packet. This parameter MUST be used together with the SecurityLevel parameter which shows the level of security in the message.

The SecurityLevel parameter shows whether the request has been authenticated. If SecurityLevel is 0, the request has NOT been authenticated (i.e. the packet signature has not been verified). For an authenticated, non encrypted request, SecurityLevel is 1. For an authenticated and encrypted request, SecurityLevel is 2.

Respond is True by default, and will automatically send a response using the value in LocalEngineId. To suppress the response, set Respond to False.

The value returned to SourceAddress for EngineBoots is always 0, and EngineTime is the number of seconds since January 1st, 1970 (GMT).

Error Event (SNMPTCPAgent Class)

Fired when information is available about errors during data delivery.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void error(SNMPTCPAgentErrorEvent e) {}
  ...
}

public class SNMPTCPAgentErrorEvent {
  public int errorCode;
  public String description;
}

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the class throws an exception.

The ErrorCode parameter contains an error code, and the Description parameter contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

GetBulkRequest Event (SNMPTCPAgent Class)

Fired when a GetBulkRequest packet is received.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void getBulkRequest(SNMPTCPAgentGetBulkRequestEvent e) {}
  ...
}

public class SNMPTCPAgentGetBulkRequestEvent {
  public int requestId;
  public int messageId;
  public int SNMPVersion;
  public String community;
  public String user;
  public int securityLevel;
  public String sourceAddress;
  public int sourcePort;
  public int nonRepeaters;
  public int maxRepetitions;
  public int errorIndex; //read-write
  public int errorStatus; //read-write
  public String errorDescription;
  public boolean respond; //read-write
}

Remarks

This is only available for SNMP versions 2 and 3.

The list of variables in the SNMP packet, including optional values and types, is provided through the Objects collection. Each object is of type SNMPObject. This type describes the Oid, ObjectType, and Value of each SNMP object. These variables must be copied to another location before the event has completed executing, or they may be overridden by other events.

The SourceAddress and SourcePort parameters show the address and port of the sender as reported by the TCP/IP stack.

The MessageId parameter identifies the received request.

For SNMPv3, the User parameter shows the user that was supplied with the packet. This parameter MUST be used together with the SecurityLevel parameter which shows the level of security in the message.

The SecurityLevel parameter shows whether the request has been authenticated. If SecurityLevel is 0, the request has NOT been authenticated (i.e. the packet signature has not been verified). For an authenticated, non encrypted request, SecurityLevel is 1. For an authenticated and encrypted request, SecurityLevel is 2.

To send a response, the Respond parameter must be set to true. By default, this value is false, which means no response will be sent. The ErrorStatus parameter may also be set to a valid SNMP status code (the default value is 0, which represents no error).

The following is a list of valid SNMP status code values:

Variable indexes start with 0. ErrorIndex has no meaning when ErrorStatus is 0 (no error).

A GetBulkRequest is very similar to a GetNextRequest, the difference is that Getbulk performs a continuous GetNext operation based on the MaxRepitions value. The NonRepeaters value will determine the number of Objects for which a simple GetNext operation should be performed. For the remaining variables, a continuous GetNext operation is performed based on the MaxRepitions value.

So if you send a request containing X objects, the agent will perform N simple GetNext operations and M continuous GetNext operations X - N times. With X being the number of objects received, N being the number of NonRepeaters, and M being the number of MaxRepitions. Thus the SNMPMgr is expecting to receive N + M x (X - N) objects, assuming that each object has M successors.

GetNextRequest Event (SNMPTCPAgent Class)

Fired when a GetNextRequest packet is received.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void getNextRequest(SNMPTCPAgentGetNextRequestEvent e) {}
  ...
}

public class SNMPTCPAgentGetNextRequestEvent {
  public int requestId;
  public int messageId;
  public int SNMPVersion;
  public String community;
  public String user;
  public int securityLevel;
  public String sourceAddress;
  public int sourcePort;
  public int errorIndex; //read-write
  public int errorStatus; //read-write
  public String errorDescription;
  public boolean respond; //read-write
}

Remarks

The list of variables in the SNMP packet, including optional values and types, is provided through the Objects collection. Each object is of type SNMPObject. This type describes the Oid, ObjectType, and Value of each SNMP object. These variables must be copied to another location before the event has completed executing, or they may be overridden by other events.

The SourceAddress and SourcePort parameters show the address and port of the sender as reported by the TCP/IP stack.

The MessageId parameter identifies the received request.

For SNMPv3, the User parameter shows the user that was supplied with the packet. This parameter MUST be used together with the SecurityLevel parameter which shows the level of security in the message.

The SecurityLevel parameter shows whether the request has been authenticated. If SecurityLevel is 0, the request has NOT been authenticated (i.e. the packet signature has not been verified). For an authenticated, non encrypted request, SecurityLevel is 1. For an authenticated and encrypted request, SecurityLevel is 2.

To send a response, the Respond parameter must be set to true. By default, this value is false, which means no response will be sent. The ErrorStatus parameter may also be set to a valid SNMP status code (the default value is 0, which represents no error).

The following is a list of valid SNMP status code values:

Variable indexes start with 0. ErrorIndex has no meaning when ErrorStatus is 0 (no error).

GetRequest Event (SNMPTCPAgent Class)

Fired when a GetRequest packet is received.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void getRequest(SNMPTCPAgentGetRequestEvent e) {}
  ...
}

public class SNMPTCPAgentGetRequestEvent {
  public int requestId;
  public int messageId;
  public int SNMPVersion;
  public String community;
  public String user;
  public int securityLevel;
  public String sourceAddress;
  public int sourcePort;
  public int errorIndex; //read-write
  public int errorStatus; //read-write
  public String errorDescription;
  public boolean respond; //read-write
}

Remarks

The list of variables in the SNMP packet, including optional values and types, is provided through the Objects collection. Each object is of type SNMPObject. This type describes the Oid, ObjectType, and Value of each SNMP object. These variables must be copied to another location before the event has completed executing, or they may be overridden by other events.

The SourceAddress and SourcePort parameters show the address and port of the sender as reported by the TCP/IP stack.

The MessageId parameter identifies the received request.

For SNMPv3, the User parameter shows the user that was supplied with the packet. This parameter MUST be used together with the SecurityLevel parameter which shows the level of security in the message.

The SecurityLevel parameter shows whether the request has been authenticated. If SecurityLevel is 0, the request has NOT been authenticated (i.e. the packet signature has not been verified). For an authenticated, non encrypted request, SecurityLevel is 1. For an authenticated and encrypted request, SecurityLevel is 2.

To send a response, the Respond parameter must be set to true. By default, this value is false, which means no response will be sent. The ErrorStatus parameter may also be set to a valid SNMP status code (the default value is 0, which represents no error).

The following is a list of valid SNMP status code values:

Variable indexes start with 0. ErrorIndex has no meaning when ErrorStatus is 0 (no error).

GetUserPassword Event (SNMPTCPAgent Class)

Retrieves a password associated with a user.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void getUserPassword(SNMPTCPAgentGetUserPasswordEvent e) {}
  ...
}

public class SNMPTCPAgentGetUserPasswordEvent {
  public int passwordType;
  public String user;
  public String password; //read-write
  public int algorithm; //read-write
}

Remarks

The GetUserPassword event is fired after initial inspection of SNMPv3 requests.

The type of password required is provided in the PasswordType parameter: 1 for authentication, and 2 for encryption (privacy).

The password corresponding to User (if any) must be provided in the Password parameter. If the password is valid, processing will continue to other events such as GetRequest, SetRequest, etc.

If the PasswordType parameter is 1 (authentication is used), the Algorithm parameter can be set. Possible values are:

If the password does not match the signature in the request, a BadPacket event will be fired, at which point you can decide whether to report the error to the client (see the description of the BadPacket event for more information).

If the User is invalid or unknown, set the password to empty string (default) to ignore the request. This will result in a BadPacket event being fired, at which point you can decide whether to report the error to the client or not.

GetUserSecurityLevel Event (SNMPTCPAgent Class)

Sets the security level for an incoming packet.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void getUserSecurityLevel(SNMPTCPAgentGetUserSecurityLevelEvent e) {}
  ...
}

public class SNMPTCPAgentGetUserSecurityLevelEvent {
  public String user;
  public byte[] engineId;
  public int securityLevel; //read-write
}

Remarks

The GetUserSecurityLevel event is fired after the first inspection of each SNMPv3 request. The SecurityLevel parameter determines the level of security for the message.

On entry, the SecurityLevel parameter contains the default security level for User if the user is located in the internal cache, or if the User is not found in the cache, the SecurityLevel will be -1.

The value of SecurityLevel upon exiting the event, determines how the message will be processed:

HashPassword Event (SNMPTCPAgent Class)

Fired before and after a password is hashed.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void hashPassword(SNMPTCPAgentHashPasswordEvent e) {}
  ...
}

public class SNMPTCPAgentHashPasswordEvent {
  public String password;
  public int authAlgorithm;
  public String hash; //read-write
}

Remarks

SNMPv3 passwords are hashed in order to obtain authentication and encryption keys. This is an expensive operation, and in certain situations it may be preferable to store the hashed passwords externally and supply them on demand.

If a hash is required, the event fires with an empty string in the Hash parameter. In this case, you can choose to supply a value for the hash and stop the class from computing the hash.

The event also fires every time a hash is computed. In this case, the Hash parameter contains the value of the computed hash.

AuthAlgorithm contains either 1 for HMAC-MD5-96, 2 for HMAC-SHA-96 or 3 for HMAC-192-SHA-256

PacketTrace Event (SNMPTCPAgent Class)

Fired for every packet sent or received.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void packetTrace(SNMPTCPAgentPacketTraceEvent e) {}
  ...
}

public class SNMPTCPAgentPacketTraceEvent {
  public byte[] packet;
  public int direction;
  public String packetAddress;
  public int packetPort;
}

Remarks

The PacketTrace event shows all the packets sent or received by the class.

Packet contains the full contents of the datagram.

Direction shows the direction of the packet: 1 for incoming packets, and 2 for outgoing packets.

In the case of an incoming packet, PacketAddress and PacketPort identify the source of the packet.

In the case of an outgoing packet, PacketAddress and PacketPort identify the destination of the packet.

ReadyToSend Event (SNMPTCPAgent Class)

Fired when the class is ready to send data.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void readyToSend(SNMPTCPAgentReadyToSendEvent e) {}
  ...
}

public class SNMPTCPAgentReadyToSendEvent {
}

Remarks

The ReadyToSend event indicates that the underlying TCP/IP subsystem is ready to accept data after a failed DataToSend(TBD. DataToSend is removed).

Report Event (SNMPTCPAgent Class)

Fired when a Report packet is received.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void report(SNMPTCPAgentReportEvent e) {}
  ...
}

public class SNMPTCPAgentReportEvent {
  public int requestId;
  public int SNMPVersion;
  public String community;
  public String user;
  public int securityLevel;
  public String sourceAddress;
  public int sourcePort;
  public int errorIndex;
  public int errorStatus;
  public String errorDescription;
}

Remarks

For SNMPv3, the User parameter shows the user that was supplied with the packet. This parameter MUST be used together with the SecurityLevel parameter which shows the level of security in the message.

The SecurityLevel parameter shows whether the request has been authenticated. If SecurityLevel is 0, the request has NOT been authenticated (i.e. the packet signature has not been verified). For an authenticated, non encrypted request, SecurityLevel is 1. For an authenticated and encrypted request, SecurityLevel is 2.

The list of variables in the SNMP packet, including optional values and types, is provided through the Objects collection. Each object is of type SNMPObject. This type describes the Oid, ObjectType, and Value of each SNMP object. These variables must be copied to another location before the event has completed executing, or they may be overridden by other events.

The SourceAddress and SourcePort parameters show the address and port of the sender as reported by the TCP/IP stack.

SetRequest Event (SNMPTCPAgent Class)

Fired when a SetRequest packet is received.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void setRequest(SNMPTCPAgentSetRequestEvent e) {}
  ...
}

public class SNMPTCPAgentSetRequestEvent {
  public int requestId;
  public int messageId;
  public int SNMPVersion;
  public String community;
  public String user;
  public int securityLevel;
  public String sourceAddress;
  public int sourcePort;
  public int errorIndex; //read-write
  public int errorStatus; //read-write
  public String errorDescription;
  public boolean respond; //read-write
}

Remarks

The list of variables in the SNMP packet, including optional values and types, is provided through the Objects collection. Each object is of type SNMPObject. This type describes the Oid, ObjectType, and Value of each SNMP object. These variables must be copied to another location before the event has completed executing, or they may be overridden by other events.

The SourceAddress and SourcePort parameters show the address and port of the sender as reported by the TCP/IP stack.

The MessageId parameter identifies the received request.

For SNMPv3, the User parameter shows the user that was supplied with the packet. This parameter MUST be used together with the SecurityLevel parameter which shows the level of security in the message.

The SecurityLevel parameter shows whether the request has been authenticated. If SecurityLevel is 0, the request has NOT been authenticated (i.e. the packet signature has not been verified). For an authenticated, non encrypted request, SecurityLevel is 1. For an authenticated and encrypted request, SecurityLevel is 2.

To send a response, the Respond parameter must be set to true. By default, this value is false, which means no response will be sent. The ErrorStatus parameter may also be set to a valid SNMP status code (the default value is 0, which represents no error).

The following is a list of valid SNMP status code values:

Variable indexes start with 0. ErrorIndex has no meaning when ErrorStatus is 0 (no error).

SSLClientAuthentication Event (SNMPTCPAgent Class)

Fired when the client presents its credentials to the server.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void SSLClientAuthentication(SNMPTCPAgentSSLClientAuthenticationEvent e) {}
  ...
}

public class SNMPTCPAgentSSLClientAuthenticationEvent {
  public String remoteAddress;
  public int remotePort;
  public byte[] certEncoded;
  public String certSubject;
  public String certIssuer;
  public String status;
  public boolean accept; //read-write
}

Remarks

This event fires when a client connects to the class and presents a certificate for authentication. The Accept parameter is a recommendation on whether to continue or close the connection. This is just a suggestion: application software must use its own logic to determine whether to continue or not.

When Accept is False, Status shows why the verification failed (otherwise, Status contains the string "OK").

RemoteAddress is the IP address of the connecting client.

RemotePort is the source port of the connecting client.

CertEncoded is the base64 encoded certificate presented by the client.

CertSubject is the subject of the certificate presented by the client.

CertIssuer is the subject of the issuer of the certificate presented by the client.

Status is the stauts of the certificate.

Accept defines whether the certificate is accepted.

SSLServerAuthentication Event (SNMPTCPAgent Class)

Fires when connecting to the server.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void SSLServerAuthentication(SNMPTCPAgentSSLServerAuthenticationEvent e) {}
  ...
}

public class SNMPTCPAgentSSLServerAuthenticationEvent {
  public String remoteAddress;
  public int remotePort;
  public byte[] certEncoded;
  public String certSubject;
  public String certIssuer;
  public String status;
  public boolean accept; //read-write
}

Remarks

This event is where the client can decide whether to continue with the connection process or not. The Accept parameter is a recommendation on whether to continue or close the connection. This is just a suggestion: application software must use its own logic to determine whether to continue or not.

When Accept is False, Status shows why the verification failed (otherwise, Status contains the string "OK"). If it is decided to continue, you can override and accept the certificate by setting the Accept parameter to True.

RemoteAddress is the IP address of the server.

RemotePort is the source port of the server.

CertEncoded is the base64 encoded certificate presented by the server.

CertSubject is the subject of the certificate presented by the server.

CertIssuer is the subject of the issuer of the certificate presented by the server.

Status is the stauts of the certificate.

Accept defines whether the certificate is accepted.

SSLStatus Event (SNMPTCPAgent Class)

Shows the progress of the secure connection.

Syntax

public class DefaultSNMPTCPAgentEventListener implements SNMPTCPAgentEventListener {
  ...
  public void SSLStatus(SNMPTCPAgentSSLStatusEvent e) {}
  ...
}

public class SNMPTCPAgentSSLStatusEvent {
  public String remoteAddress;
  public int remotePort;
  public String message;
}

Remarks

The event is fired for informational and logging purposes only. It is used to track the progress of the connection.

RemoteAddress is the IP address of the remote machine.

RemotePort is the port of the remote machine.

Message is the log message.

Certificate Type

This is the digital certificate being used.

Remarks

This type describes the current digital certificate. The certificate may be a public or private key. The fields are used to identify or select certificates.

Fields

Constructors

public Certificate();

public Certificate( certificateFile);

public Certificate( encoded);

public Certificate( storeType,  store,  storePassword,  subject);

public Certificate( storeType,  store,  storePassword,  subject,  configurationString);

public Certificate( storeType,  store,  storePassword,  encoded);

public Certificate( storeType,  store,  storePassword,  subject);

public Certificate( storeType,  store,  storePassword,  subject,  configurationString);

public Certificate( storeType,  store,  storePassword,  encoded);

SNMPObject Type

The current SNMP object.

Remarks

This type defines an SNMP object. Each object has an Oid, ObjectType, and Value. These values are populated by the class when incoming packets are received. You may use these fields to define objects to be used in outgoing packets.

Fields

Constructors

public SNMPObject();

public SNMPObject( oid);

public SNMPObject( oid,  value);

public SNMPObject( oid,  value,  objectType);

Config Settings (SNMPTCPAgent Class)

SNMPTCPAgent Config Settings

TCPClient Config Settings

SSL Config Settings

-----BEGIN CERTIFICATE-----
MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw
... Intermediate Cert ...
eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w
F0I1XhM+pKj7FjDr+XNj
-----END CERTIFICATE-----
\r \n
-----BEGIN CERTIFICATE-----
MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp
... Root Cert ...
d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA
-----END CERTIFICATE-----

-----BEGIN CERTIFICATE-----
MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw
... Intermediate Cert ...
eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w
F0I1XhM+pKj7FjDr+XNj
-----END CERTIFICATE-----
\r \n
-----BEGIN CERTIFICATE-----
MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp
... Root Cert ...
d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA
-----END CERTIFICATE-----

-----BEGIN CERTIFICATE-----
MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw
... Intermediate Cert...
eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w
F0I1XhM+pKj7FjDr+XNj
-----END CERTIFICATE-----
\r \n
-----BEGIN CERTIFICATE-----
MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp
... Root Cert...
d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA
-----END CERTIFICATE-----

Socket Config Settings

Base Config Settings

Trappable Errors (SNMPTCPAgent Class)

SNMPTCPAgent Errors

TCPClient Errors

SSL Errors

TCP/IP Errors