SysLog Component

Properties   Methods   Events   Config Settings   Errors  

The Syslog component is used to send and receive network system log packets.

Syntax

TipwSysLog

Remarks

The Syslog component implements a lightweight BSD syslog client as specified in RFC 3164 (UDP), RFC 5425 (SSL/TLS), and RFC 6587 (TCP). The component is used to send and receive BSD system network logging packets.

The first step in using the Syslog component is to set LocalHost and LocalPort to the interface and port on which the host will be receiving syslog packets, then set Active to True. For each packet, the component will parse the headers and message and fire a PacketIn event.

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.

Active Property (SysLog 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.

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

This property is not available at design time.

LocalHost Property (SysLog 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 (SysLog Component)

The port in the local host where Syslog binds.

Syntax

property LocalPort: Integer read get_LocalPort write set_LocalPort;

Default Value

514

Remarks

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

Setting it to 0 (default) enables the TCP/IP stack to choose a port at random. The chosen port will be shown by the LocalPort property after the connection is established.

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.

The LocalPort property is useful when trying to connect to services that require a trusted port in the client side.

RemoteHost Property (SysLog Component)

Sets a specific host for outgoing log packets.

Syntax

property RemoteHost: String read get_RemoteHost write set_RemoteHost;

Default Value

'255.255.255.255'

Remarks

When a call is made to the SendPacket method, the component will send it to whatever value is in RemoteHost. The default value is the broadcast address, "255.255.255.255".

RemotePort Property (SysLog Component)

Sets a specific port for outgoing log packets.

Syntax

property RemotePort: Integer read get_RemotePort write set_RemotePort;

Default Value

514

Remarks

When a call is made to the SendPacket method, the component will send to RemoteHost on RemotePort. The default value is 514, the standard port as defined in the BSD syslog RFC 3164.

SSLAcceptServerCertEncoded Property (SysLog Component)

This is the certificate (PEM/Base64 encoded).

Syntax

property SSLAcceptServerCertEncoded: String read get_SSLAcceptServerCertEncoded write set_SSLAcceptServerCertEncoded;
property SSLAcceptServerCertEncodedB: TBytes read get_SSLAcceptServerCertEncodedB write set_SSLAcceptServerCertEncodedB;

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.

SSLAuthenticateClients Property (SysLog 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 (SysLog 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 (SysLog 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 (SysLog 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 (SysLog Component)

This is the type of certificate store for this certificate.

Syntax

property SSLCertStoreType: TipwCertStoreTypes read get_SSLCertStoreType write set_SSLCertStoreType;

TipwCertStoreTypes = (
  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 (SysLog 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 (SysLog 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: TLS/SSL can only be used when UseTCP is True.

This property is not available at design time.

SSLServerCertEncoded Property (SysLog Component)

This is the certificate (PEM/Base64 encoded).

Syntax

property SSLServerCertEncoded: String read get_SSLServerCertEncoded;
property SSLServerCertEncodedB: TBytes read get_SSLServerCertEncodedB;

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 read-only and not available at design time.

UseTCP Property (SysLog Component)

Whether to use TCP.

Syntax

property UseTCP: Boolean read get_UseTCP write set_UseTCP;

Default Value

false

Remarks

This property specifies whether TCP is used. By default this proprety is False and UDP is used. When set to True TCP will be used as the underlying protocol.

When set to True the following additional settings are also applicable:

• SSLAuthenticateClients
• SSLEnabled
• SSLAcceptServerCert*
• SSLCert*
• SSLServerCert*
• TCPMessageDelimiter

Activate Method (SysLog Component)

Enables sending and receiving of data.

Syntax

procedure Activate();

Remarks

This method enables sending and receiving of data. When called the component will create a communication endpoint (socket) which can be used for sending and receiving UDP messages. This method must be called before using the component to send and receive data.

If the UseConnection configuration setting is set to True, then a local association (connection) to the remote host is also created.

Config Method (SysLog 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 (SysLog Component)

Disables sending and receive of data.

Syntax

procedure Deactivate();

Remarks

This method disables sending and receiving of data. When called the component will destroy the existing socket and disable data communications.

DoEvents Method (SysLog 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.

Reset Method (SysLog Component)

Reset the component.

Syntax

procedure Reset();

Remarks

This method will reset the component's properties to their default values.

ResolveRemoteHost Method (SysLog Component)

Resolves the hostname in RemoteHost to an IP address.

Syntax

procedure ResolveRemoteHost();

Remarks

This method resolves the hostname specified by RemoteHost to an IP address. The resolved value is available in the RemoteHost property after this method returns.

In most cases calling this method is not necessary, the component will resolve the hostname automatically when necessary. If DelayHostResolution is True this method may be called to manually resolve RemoteHost if desired.

SendPacket Method (SysLog Component)

Send a log packet to RemoteHost .

Syntax

procedure SendPacket(Facility: Integer; Severity: Integer; Message: String);

Remarks

System log packets are composed of three main sections, each of which can be broken down into two smaller pieces.

The first section is the PRI, which contains the originating Facility and Severity of the Message. Facility is a value from 0 to 23, with each value being a different part of the system:

Severity is a value from 0 to 7 using the following convention:

The section sections contains a timestamp and hostname, both of which are automatically generated by the component. The third section is the Message itself.

Connected Event (SysLog 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 (SysLog Component)

Fired to indicate changes in a 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:

StatusCode has the error code returned by the Transmission Control Protocol (TCP)/IP stack. Description contains a description of this code. The value of StatusCode is equal to the value of the error.

Disconnected Event (SysLog 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 when a connection is closed.

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.

Error Event (SysLog 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.

PacketIn Event (SysLog Component)

Fires whenever a system log packet is received.

Syntax

type TPacketInEvent = procedure (
  Sender: TObject;
  FacilityCode: Integer;
  const Facility: String;
  SeverityCode: Integer;
  const Severity: String;
  const Timestamp: String;
  const Hostname: String;
  const Message: String;
  Conforms: Boolean;
  Packet: String;
  PacketB: TBytes;
  const SourceAddress: String;
  SourcePort: Integer
) of Object;

property OnPacketIn: TPacketInEvent read FOnPacketIn write FOnPacketIn;

Remarks

System log packets are composed of three main sections, each of which can be broken down into two smaller pieces.

The first section is the PRI, which contains the originating FacilityCode and SeverityCode of the Message. FacilityCode is a value from 0 to 23, with each value being a different part of the system. Facility is a string representation of FacilityCode based on the following convention:

SeverityCode is a value from 0 to 7. Severity is a string representation of SeverityCode using the following convention:

The second section contains the Timestamp and Hostname. Timestamp is a string that should conform to the standard structure "MMM DD, HH:MM:SS". The component will search for the Timestamp and verify that it conforms. If it conforms, the component will set Hostname, otherwise, everything after the PRI will be placed in Message.

If Conforms is TRUE, then the original syslog packet conforms to the syslog RFC and Timestamp, Hostname, and Message will all have valid values. Otherwise, you should parse the contents of Packet to verify the fields manually.

SourceAddress and SourcePort are the address and port from which Packet was sent. This can be an intermediate syslog server that is simply forwarding packets from the original host.

SSLClientAuthentication Event (SysLog 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.

SSLServerAuthentication Event (SysLog Component)

Fires when connecting to the server.

Syntax

type TSSLServerAuthenticationEvent = 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 OnSSLServerAuthentication: TSSLServerAuthenticationEvent read FOnSSLServerAuthentication write FOnSSLServerAuthentication;

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 (SysLog 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.

Config Settings (SysLog Component)

The component accepts one or more of the following configuration settings. Configuration 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.

Syslog Config Settings

UDP Config Settings

Socket Config Settings

Base Config Settings

Trappable Errors (SysLog Component)

SysLog Errors

	451   Unable to acquire valid system time.

UDP Errors

	104   UDP is already Active.
	106   You cannot change the LocalPort while the component is Active.
	107   You cannot change the LocalHost at this time. A connection is in progress.
	109   The component must be Active for this operation.
	112   Cannot change MaxPacketSize while the component is Active.
	113   Cannot change ShareLocalPort option while the component is Active.
	114   Cannot change RemoteHost when UseConnection is set and the component Active.
	115   Cannot change RemotePort when UseConnection is set and the component is Active.
	116   RemotePort can't be zero when UseConnection is set. Please specify a valid service port number.
	117   Cannot change UseConnection while the component is Active.
	118   Message can't be longer than MaxPacketSize.
	119   Message too short.
	434   Unable to convert string to selected CodePage

SSL Errors

	270   Cannot load specified security library.
	271   Cannot open certificate store.
	272   Cannot find specified certificate.
	273   Cannot acquire security credentials.
	274   Cannot find certificate chain.
	275   Cannot verify certificate chain.
	276   Error during handshake.
	280   Error verifying certificate.
	281   Could not find client certificate.
	282   Could not find server certificate.
	283   Error encrypting data.
	284   Error decrypting data.

TCP/IP Errors

	10004   [10004] Interrupted system call.
	10009   [10009] Bad file number.
	10013   [10013] Access denied.
	10014   [10014] Bad address.
	10022   [10022] Invalid argument.
	10024   [10024] Too many open files.
	10035   [10035] Operation would block.
	10036   [10036] Operation now in progress.
	10037   [10037] Operation already in progress.
	10038   [10038] Socket operation on non-socket.
	10039   [10039] Destination address required.
	10040   [10040] Message too long.
	10041   [10041] Protocol wrong type for socket.
	10042   [10042] Bad protocol option.
	10043   [10043] Protocol not supported.
	10044   [10044] Socket type not supported.
	10045   [10045] Operation not supported on socket.
	10046   [10046] Protocol family not supported.
	10047   [10047] Address family not supported by protocol family.
	10048   [10048] Address already in use.
	10049   [10049] Can't assign requested address.
	10050   [10050] Network is down.
	10051   [10051] Network is unreachable.
	10052   [10052] Net dropped connection or reset.
	10053   [10053] Software caused connection abort.
	10054   [10054] Connection reset by peer.
	10055   [10055] No buffer space available.
	10056   [10056] Socket is already connected.
	10057   [10057] Socket is not connected.
	10058   [10058] Can't send after socket shutdown.
	10059   [10059] Too many references, can't splice.
	10060   [10060] Connection timed out.
	10061   [10061] Connection refused.
	10062   [10062] Too many levels of symbolic links.
	10063   [10063] File name too long.
	10064   [10064] Host is down.
	10065   [10065] No route to host.
	10066   [10066] Directory not empty
	10067   [10067] Too many processes.
	10068   [10068] Too many users.
	10069   [10069] Disc Quota Exceeded.
	10070   [10070] Stale NFS file handle.
	10071   [10071] Too many levels of remote in path.
	10091   [10091] Network subsystem is unavailable.
	10092   [10092] WINSOCK DLL Version out of range.
	10093   [10093] Winsock not loaded yet.
	11001   [11001] Host not found.
	11002   [11002] Non-authoritative 'Host not found' (try again or check DNS setup).
	11003   [11003] Non-recoverable errors: FORMERR, REFUSED, NOTIMP.
	11004   [11004] Valid name, no data record (check DNS setup).