SNMPTCPTrapMgr Component

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The SNMPTCPTrapMgr component provides a TCP-based listening point for SNMP traps.

Syntax

TipnSNMPTCPTrapMgr

Remarks

The SNMPTCPTrapMgr component provides a TCP-based listening point for SNMP traps and informs as specified by the SNMP RFCs. The component supports v1, v2c, and v3 traps.

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

The component 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.

Messages are received through events such as Trap, InformRequest, or DiscoveryRequest.

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

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 AddUser, RemoveUser, ShowCache, ClearCache, AddEngine, and RemoveEngine 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.

Property List

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

Method List

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

Event List

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

Config Settings

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

AcceptData Property (SNMPTCPTrapMgr Component)

Enables or disables data reception.

Syntax

property AcceptData: Boolean read get_AcceptData write set_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 (SNMPTCPTrapMgr Component)

Indicates whether the component is active.

Syntax

property Active: Boolean read get_Active write set_Active;

Default Value

false

Remarks

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

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

Note: Use the Activate or Deactivate method to control whether the component is active.

This property is not available at design time.

LocalEngineId Property (SNMPTCPTrapMgr Component)

The Engine Id (for SNMPv3).

Syntax

property LocalEngineId: String read get_LocalEngineId write set_LocalEngineId;
property LocalEngineIdB: TBytes read get_LocalEngineIdB write set_LocalEngineIdB;

Default Value

''

Remarks

This property is necessary for properly handling InformRequest packets.

LocalHost Property (SNMPTCPTrapMgr Component)

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

Syntax

property LocalHost: String read get_LocalHost write set_LocalHost;

Default Value

''

Remarks

The LocalHost 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 multi-homed hosts (machines with more than one IP interface) setting LocalHost to the value of an interface will make the component initiate connections (or accept in the case of server components) only through that interface.

If the component 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 multi-homed 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 (SNMPTCPTrapMgr Component)

The port in the local host where the component is bound to.

Syntax

property LocalPort: Integer read get_LocalPort write set_LocalPort;

Default Value

162

Remarks

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

The default port is 162 (standard trap port). If that port is busy, an error will be returned, unless the ForceLocalPort configuration setting is set to False, in which case a random port will be chosen.

LocalPort cannot be changed once the component is Active. Any attempt to set the LocalPort property when the component 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 (SNMPTCPTrapMgr Component)

The objects in the current request.

Syntax

property Objects: TipnSNMPObjectList read get_Objects write set_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.

RequestId Property (SNMPTCPTrapMgr Component)

The request-id to mark outgoing packets with.

Syntax

property RequestId: Integer read get_RequestId write set_RequestId;

Default Value

1

Remarks

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

This property is not available at design time.

SSLAuthenticateClients Property (SNMPTCPTrapMgr Component)

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

Syntax

property SSLAuthenticateClients: Boolean read get_SSLAuthenticateClients write set_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.

SSLCertEncoded Property (SNMPTCPTrapMgr Component)

This is the certificate (PEM/Base64 encoded).

Syntax

property SSLCertEncoded: String read get_SSLCertEncoded write set_SSLCertEncoded;
property SSLCertEncodedB: TBytes read get_SSLCertEncodedB write set_SSLCertEncodedB;

Default Value

''

Remarks

This is the certificate (PEM/Base64 encoded). This property is used to assign a specific certificate. The Store and Subject properties also may be used to specify a certificate.

When Encoded is set, a search is initiated in the current Store for the private key of the certificate. If the key is found, Subject is updated to reflect the full subject of the selected certificate; otherwise, Subject is set to an empty string.

This property is not available at design time.

SSLCertStore Property (SNMPTCPTrapMgr Component)

This is the name of the certificate store for the client certificate.

Syntax

property SSLCertStore: String read get_SSLCertStore write set_SSLCertStore;
property SSLCertStoreB: TBytes read get_SSLCertStoreB write set_SSLCertStoreB;

Default Value

'MY'

Remarks

This is the name of the certificate store for the client certificate.

The StoreType property denotes the type of the certificate store specified by Store. If the store is password protected, specify the password in StorePassword.

Store is used in conjunction with the Subject property to specify client certificates. If Store has a value, and Subject or Encoded is set, a search for a certificate is initiated. Please see the Subject property for details.

Designations of certificate stores are platform dependent.

The following designations are the most common User and Machine certificate stores in Windows:

When the certificate store type is PFXFile, this property must be set to the name of the file. When the type is PFXBlob, the property must be set to the binary contents of a PFX file (i.e., PKCS#12 certificate store).

SSLCertStorePassword Property (SNMPTCPTrapMgr Component)

If the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.

Syntax

property SSLCertStorePassword: String read get_SSLCertStorePassword write set_SSLCertStorePassword;

Default Value

''

Remarks

If the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.

SSLCertStoreType Property (SNMPTCPTrapMgr Component)

This is the type of certificate store for this certificate.

Syntax

property SSLCertStoreType: TipnCertStoreTypes read get_SSLCertStoreType write set_SSLCertStoreType;

TipnCertStoreTypes = (
  cstUser,
  cstMachine,
  cstPFXFile,
  cstPFXBlob,
  cstJKSFile,
  cstJKSBlob,
  cstPEMKeyFile,
  cstPEMKeyBlob,
  cstPublicKeyFile,
  cstPublicKeyBlob,
  cstSSHPublicKeyBlob,
  cstP7BFile,
  cstP7BBlob,
  cstSSHPublicKeyFile,
  cstPPKFile,
  cstPPKBlob,
  cstXMLFile,
  cstXMLBlob,
  cstJWKFile,
  cstJWKBlob,
  cstSecurityKey,
  cstBCFKSFile,
  cstBCFKSBlob,
  cstPKCS11,
  cstAuto
);

Default Value

cstUser

Remarks

This is the type of certificate store for this certificate.

The component supports both public and private keys in a variety of formats. When the cstAuto value is used, the component will automatically determine the type. This property can take one of the following values:

SSLCertSubject Property (SNMPTCPTrapMgr Component)

This is the subject of the certificate used for client authentication.

Syntax

property SSLCertSubject: String read get_SSLCertSubject write set_SSLCertSubject;

Default Value

''

Remarks

This is the subject of the certificate used for client authentication.

This property must be set after all other certificate properties are set. When this property is set, a search is performed in the current certificate store to locate a certificate with a matching subject.

If a matching certificate is found, the property is set to the full subject of the matching certificate.

If an exact match is not found, the store is searched for subjects containing the value of the property.

If a match is still not found, the property is set to an empty string, and no certificate is selected.

The special value "*" picks a random certificate in the certificate store.

The certificate subject is a comma-separated list of distinguished name fields and values. For instance, "CN=www.server.com, OU=test, C=US, E=support@nsoftware.com". Common fields and their meanings are as follows:

If a field value contains a comma, it must be quoted.

SSLEnabled Property (SNMPTCPTrapMgr Component)

Whether TLS/SSL is enabled.

Syntax

property SSLEnabled: Boolean read get_SSLEnabled write set_SSLEnabled;

Default Value

false

Remarks

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

Note: SSL is not currently supported in this product. This setting is reserved for future user.

This property is not available at design time.

Activate Method (SNMPTCPTrapMgr Component)

Activates the component.

Syntax

procedure Activate();

Remarks

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

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

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

AddEngine Method (SNMPTCPTrapMgr Component)

Adds the engine specified by EngineId to the internal authentication cache.

Syntax

procedure AddEngine(EngineId: TBytes; EngineBoots: Integer; EngineTime: Integer);

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.

If the engine parameters are unknown, the SNMPMgr component's Discover method can be used to perform a discovery with the agent. The RemoteEngineId, RemoteEngineTime, and RemoteEngineBoots properties will hold the values that can then be passed to this method.

AddUser Method (SNMPTCPTrapMgr Component)

Adds a user for the engine specified by EngineId to the internal authentication cache.

Syntax

procedure AddUser(User: String; EngineId: TBytes; AuthenticationProtocol: Integer; AuthenticationPassword: String; EncryptionAlgorithm: Integer; EncryptionPassword: String);

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:

ClearCache Method (SNMPTCPTrapMgr Component)

Clears the internal authentication database.

Syntax

procedure ClearCache();

Remarks

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

Config Method (SNMPTCPTrapMgr Component)

Sets or retrieves a configuration setting.

Syntax

function Config(ConfigurationString: String): String;

Remarks

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

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, 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 (SNMPTCPTrapMgr Component)

Deactivates the component.

Syntax

procedure 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 (SNMPTCPTrapMgr Component)

Processes events from the internal message queue.

Syntax

procedure DoEvents();

Remarks

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

HashPasswords Method (SNMPTCPTrapMgr Component)

Hashes all passwords in the cache.

Syntax

procedure 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.

RemoveEngine Method (SNMPTCPTrapMgr Component)

Removes the engine specified by EngineId from the internal authentication cache.

Syntax

procedure RemoveEngine(EngineId: TBytes);

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.

RemoveUser Method (SNMPTCPTrapMgr Component)

Removes the user specified by User of the engine specified by EngineId from the internal authentication cache.

Syntax

procedure RemoveUser(User: String; EngineId: TBytes);

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 (SNMPTCPTrapMgr Component)

Clears the object arrays.

Syntax

procedure 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).

ShowCache Method (SNMPTCPTrapMgr Component)

Lists all entries in the internal user and engine database.

Syntax

procedure ShowCache();

Remarks

A CacheEntry event is fired for every record in the database.

Value Method (SNMPTCPTrapMgr Component)

Returns the value corresponding to an OID.

Syntax

function Value(OID: String): String;

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 (SNMPTCPTrapMgr Component)

Fired for erroneous and/or malformed messages.

Syntax

type TBadPacketEvent = procedure (
  Sender: TObject;
  Packet: String;
  PacketB: TBytes;
  const SourceAddress: String;
  SourcePort: Integer;
  ErrorCode: Integer;
  const ErrorDescription: String;
  var Report: Boolean
) of Object;

property OnBadPacket: TBadPacketEvent read FOnBadPacket write FOnBadPacket;

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 (SNMPTCPTrapMgr Component)

Shows engines and users in the internal cache.

Syntax

type TCacheEntryEvent = procedure (
  Sender: TObject;
  EngineId: String;
  EngineIdB: TBytes;
  EngineBoots: Integer;
  EngineTime: Integer;
  const User: String;
  const AuthenticationProtocol: String;
  const AuthenticationPassword: String;
  const EncryptionAlgorithm: String;
  const EncryptionPassword: String
) of Object;

property OnCacheEntry: TCacheEntryEvent read FOnCacheEntry write FOnCacheEntry;

Remarks

CacheEntry events are triggered by a call to ShowCache. One event is fired for each user and engine. If there are no users for a particular engine, a single event is fired with the engine information, but empty values for user information.

CheckEngine Event (SNMPTCPTrapMgr Component)

Fired to check engine parameters (timeliness, etc.).

Syntax

type TCheckEngineEvent = procedure (
  Sender: TObject;
  EngineId: String;
  EngineIdB: TBytes;
  EngineBoots: Integer;
  EngineTime: Integer;
  const User: String;
  SecurityLevel: Integer;
  const RemoteAddress: String;
  RemotePort: Integer;
  IsNew: Boolean;
  var Accept: Boolean
) of Object;

property OnCheckEngine: TCheckEngineEvent read FOnCheckEngine write FOnCheckEngine;

Remarks

The Accept parameter determines if the engine will be accepted or not. If you set Accept to False prior to exiting the event, the processing on the message will stop and a BadPacket event will be fired.

The default value of Accept is True if and only if:

a) the engine already exists in the internal authentication cache (the IsNew parameter is False) and the timeliness has been verified;

b) the engine does not exist in the internal authentication cache (the IsNew parameter is True), but the packet has been authenticated by the component (SecurityLevel >= 1).

In all other cases, the default value for Accept is False, and you are responsible for accepting or not accepting the engine based on other considerations.

If Accept is true upon event exit, then:

a) if the engine already exists in the internal authentication cache, its time is updated to reflect the new time and the processing of the packet continues;

b) if the engine does not exist in the internal authentication cache, it is added there and if User is authenticated, the User will be added too.

Connected Event (SNMPTCPTrapMgr Component)

Fired immediately after a connection completes (or fails).

Syntax

type TConnectedEvent = procedure (
  Sender: TObject;
  const RemoteAddress: String;
  RemotePort: Integer;
  StatusCode: Integer;
  const Description: String
) of Object;

property OnConnected: TConnectedEvent read FOnConnected write FOnConnected;

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 (SNMPTCPTrapMgr Component)

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

Syntax

type TConnectionStatusEvent = procedure (
  Sender: TObject;
  const ConnectionEvent: String;
  StatusCode: Integer;
  const Description: String
) of Object;

property OnConnectionStatus: TConnectionStatusEvent read FOnConnectionStatus write FOnConnectionStatus;

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 (SNMPTCPTrapMgr Component)

Fired when a connection is closed.

Syntax

type TDisconnectedEvent = procedure (
  Sender: TObject;
  const RemoteAddress: String;
  RemotePort: Integer;
  StatusCode: Integer;
  const Description: String
) of Object;

property OnDisconnected: TDisconnectedEvent read FOnDisconnected write FOnDisconnected;

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 (SNMPTCPTrapMgr Component)

Fired when an SNMPv3 discovery packet is received.

Syntax

type TDiscoveryRequestEvent = procedure (
  Sender: TObject;
  EngineId: String;
  EngineIdB: TBytes;
  EngineBoots: Integer;
  EngineTime: Integer;
  const User: String;
  SecurityLevel: Integer;
  const SourceAddress: String;
  SourcePort: Integer;
  var Respond: Boolean
) of Object;

property OnDiscoveryRequest: TDiscoveryRequestEvent read FOnDiscoveryRequest write FOnDiscoveryRequest;

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 (SNMPTCPTrapMgr Component)

Fired when information is available about errors during data delivery.

Syntax

type TErrorEvent = procedure (
  Sender: TObject;
  ErrorCode: Integer;
  const Description: String
) of Object;

property OnError: TErrorEvent read FOnError write FOnError;

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the component raises 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.

GetUserPassword Event (SNMPTCPTrapMgr Component)

Retrieves a password associated with a user.

Syntax

type TGetUserPasswordEvent = procedure (
  Sender: TObject;
  PasswordType: Integer;
  const User: String;
  EngineId: String;
  EngineIdB: TBytes;
  var Password: String;
  var Algorithm: Integer
) of Object;

property OnGetUserPassword: TGetUserPasswordEvent read FOnGetUserPassword write FOnGetUserPassword;

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 and EngineId 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 (SNMPTCPTrapMgr Component)

Sets the security level for an incoming packet.

Syntax

type TGetUserSecurityLevelEvent = procedure (
  Sender: TObject;
  const User: String;
  EngineId: String;
  EngineIdB: TBytes;
  var SecurityLevel: Integer
) of Object;

property OnGetUserSecurityLevel: TGetUserSecurityLevelEvent read FOnGetUserSecurityLevel write FOnGetUserSecurityLevel;

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 (SNMPTCPTrapMgr Component)

Fired before and after a password is hashed.

Syntax

type THashPasswordEvent = procedure (
  Sender: TObject;
  const Password: String;
  AuthAlgorithm: Integer;
  var Hash: String
) of Object;

property OnHashPassword: THashPasswordEvent read FOnHashPassword write FOnHashPassword;

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 component 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

InformRequest Event (SNMPTCPTrapMgr Component)

Fired when an InformRequest packet is received.

Syntax

type TInformRequestEvent = procedure (
  Sender: TObject;
  RequestId: Integer;
  SNMPVersion: Integer;
  const Community: String;
  const User: String;
  SecurityLevel: Integer;
  const SourceAddress: String;
  SourcePort: Integer;
  var ErrorIndex: Integer;
  var ErrorStatus: Integer;
  const ErrorDescription: String;
  var Respond: Boolean
) of Object;

property OnInformRequest: TInformRequestEvent read FOnInformRequest write FOnInformRequest;

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 user in an InformRequest packet (SNMPv3) must be a valid user in the internal authentication cache (see the AddUser method and the CheckEngine event for more information). If not, the request is rejected, and a BadPacket event is fired before InformRequest is fired.

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).

PacketTrace Event (SNMPTCPTrapMgr Component)

Fired for every packet sent or received.

Syntax

type TPacketTraceEvent = procedure (
  Sender: TObject;
  Packet: String;
  PacketB: TBytes;
  Direction: Integer;
  const PacketAddress: String;
  PacketPort: Integer
) of Object;

property OnPacketTrace: TPacketTraceEvent read FOnPacketTrace write FOnPacketTrace;

Remarks

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

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.

SSLClientAuthentication Event (SNMPTCPTrapMgr Component)

Fired when the client presents its credentials to the server.

Syntax

type TSSLClientAuthenticationEvent = procedure (
  Sender: TObject;
  const RemoteAddress: String;
  RemotePort: Integer;
  CertEncoded: String;
  CertEncodedB: TBytes;
  const CertSubject: String;
  const CertIssuer: String;
  const Status: String;
  var Accept: Boolean
) of Object;

property OnSSLClientAuthentication: TSSLClientAuthenticationEvent read FOnSSLClientAuthentication write FOnSSLClientAuthentication;

Remarks

This event fires when a client connects to the component 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.

SSLStatus Event (SNMPTCPTrapMgr Component)

Shows the progress of the secure connection.

Syntax

type TSSLStatusEvent = procedure (
  Sender: TObject;
  const RemoteAddress: String;
  RemotePort: Integer;
  const Message: String
) of Object;

property OnSSLStatus: TSSLStatusEvent read FOnSSLStatus write FOnSSLStatus;

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.

Trap Event (SNMPTCPTrapMgr Component)

Fired when a SNMP trap packet is received.

Syntax

type TTrapEvent = procedure (
  Sender: TObject;
  RequestId: Integer;
  SNMPVersion: Integer;
  const Community: String;
  const User: String;
  SecurityLevel: Integer;
  const TrapOID: String;
  TimeStamp: Int64;
  const AgentAddress: String;
  const SourceAddress: String;
  SourcePort: Integer
) of Object;

property OnTrap: TTrapEvent read FOnTrap write FOnTrap;

Remarks

The TrapOID and TimeStamp parameters contain the Trap OID and TimeStamp. In the case of an SNMPv1 trap, there are two possible scenarios:

First, if the enterprise of the trap is "1.3.6.1.6.3.1.1.5", TrapOID will be a concatenation of TrapEnterprise and GenericTrap + 1. For instance a TrapOID of "1.3.6.1.6.3.1.1.5.5" has a TrapEnterprise of "1.3.6.1.6.3.1.1.5" and a GenericTrap of "4".

Second, In all other cases TrapOID will be a concatenation of the values for TrapEnterprise, GenericTrap, and SpecificTrap, separated by '.'.

For SNMPv2 and above, they are read from the variable-value list (if available).

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.

Some parameters are only applicable depending on the SNMPVersion value. The table below shows which parameters are applicable to which SNMP versions.

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 component when incoming packets are received. You may use these fields to define objects to be used in outgoing packets.

Fields

Constructors

constructor Create();

constructor Create(valOid: String);

constructor Create(valOid: String; valValue: TBytes);

Config Settings (SNMPTCPTrapMgr Component)

SNMPTCPTrapMgr Config Settings

TCPClient Config Settings

SSL Config Settings

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

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

Socket Config Settings

Base Config Settings

Trappable Errors (SNMPTCPTrapMgr Component)

SNMPTCPTrapMgr Errors

The component may also return one of the following error codes, which are inherited from other components.

TCPClient Errors

SSL Errors

TCP/IP Errors