SysLog Control

Properties   Methods   Events   Config Settings   Errors  

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

Syntax

SysLog

Remarks

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

The first step in using the Syslog control 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 control will parse the headers and message and fire a PacketIn event.

Property List

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

Method List

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

Event List

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

Config Settings

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

Active Property (SysLog Control)

Indicates whether the control is active.

Syntax

syslogcontrol.Active[=boolean]

Default Value

False

Remarks

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

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

This property is not available at design time.

Data Type

Boolean

LocalHost Property (SysLog Control)

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

Syntax

syslogcontrol.LocalHost[=string]

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 control initiate connections (or accept in the case of server controls) only through that interface.

If the control 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.

Data Type

String

LocalPort Property (SysLog Control)

The port in the local host where Syslog binds.

Syntax

syslogcontrol.LocalPort[=integer]

Default Value

514

Remarks

The LocalPort property must be set before Syslog is activated (Active is set to True). It instructs the control 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 control is Active. Any attempt to set the LocalPort property when the control 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.

Data Type

Integer

RemoteHost Property (SysLog Control)

Sets a specific host for outgoing log packets.

Syntax

syslogcontrol.RemoteHost[=string]

Default Value

"255.255.255.255"

Remarks

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

Data Type

String

RemotePort Property (SysLog Control)

Sets a specific port for outgoing log packets.

Syntax

syslogcontrol.RemotePort[=integer]

Default Value

514

Remarks

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

Data Type

Integer

SSLAcceptServerCertEncoded Property (SysLog Control)

This is the certificate (PEM/Base64 encoded).

Syntax

syslogcontrol.SSLAcceptServerCertEncoded[=string]

Default Value

""

Remarks

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

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

To read or write binary data to the property, a Variant (Byte Array) version is provided in .SSLAcceptServerCertEncodedB.

This property is not available at design time.

Data Type

Binary String

SSLAuthenticateClients Property (SysLog Control)

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

Syntax

syslogcontrol.SSLAuthenticateClients[=boolean]

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.

Data Type

Boolean

SSLCertEncoded Property (SysLog Control)

This is the certificate (PEM/Base64 encoded).

Syntax

syslogcontrol.SSLCertEncoded[=string]

Default Value

""

Remarks

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

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

To read or write binary data to the property, a Variant (Byte Array) version is provided in .SSLCertEncodedB.

This property is not available at design time.

Data Type

Binary String

SSLCertStore Property (SysLog Control)

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

Syntax

syslogcontrol.SSLCertStore[=string]

Default Value

"MY"

Remarks

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

The SSLCertStoreType property denotes the type of the certificate store specified by SSLCertStore. If the store is password protected, specify the password in SSLCertStorePassword.

SSLCertStore is used in conjunction with the SSLCertSubject property to specify client certificates. If SSLCertStore has a value, and SSLCertSubject or SSLCertEncoded is set, a search for a certificate is initiated. Please see the SSLCertSubject 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).

To read or write binary data to the property, a Variant (Byte Array) version is provided in .SSLCertStoreB.

Data Type

Binary String

SSLCertStorePassword Property (SysLog Control)

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

Syntax

syslogcontrol.SSLCertStorePassword[=string]

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.

Data Type

String

SSLCertStoreType Property (SysLog Control)

This is the type of certificate store for this certificate.

Syntax

syslogcontrol.SSLCertStoreType[=integer]

Possible Values

cstUser(0), 
cstMachine(1), 
cstPFXFile(2), 
cstPFXBlob(3), 
cstJKSFile(4), 
cstJKSBlob(5), 
cstPEMKeyFile(6), 
cstPEMKeyBlob(7), 
cstPublicKeyFile(8), 
cstPublicKeyBlob(9), 
cstSSHPublicKeyBlob(10), 
cstP7BFile(11), 
cstP7BBlob(12), 
cstSSHPublicKeyFile(13), 
cstPPKFile(14), 
cstPPKBlob(15), 
cstXMLFile(16), 
cstXMLBlob(17), 
cstJWKFile(18), 
cstJWKBlob(19), 
cstSecurityKey(20), 
cstBCFKSFile(21), 
cstBCFKSBlob(22), 
cstPKCS11(23), 
cstAuto(99)

Default Value

0

Remarks

This is the type of certificate store for this certificate.

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

Data Type

Integer

SSLCertSubject Property (SysLog Control)

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

Syntax

syslogcontrol.SSLCertSubject[=string]

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.

Data Type

String

SSLEnabled Property (SysLog Control)

Whether TLS/SSL is enabled.

Syntax

syslogcontrol.SSLEnabled[=boolean]

Default Value

False

Remarks

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

Note: TLS/SSL can only be used when UseTCP is .

This property is not available at design time.

Data Type

Boolean

SSLServerCertEncoded Property (SysLog Control)

This is the certificate (PEM/Base64 encoded).

Syntax

syslogcontrol.SSLServerCertEncoded

Default Value

""

Remarks

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

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

To read or write binary data to the property, a Variant (Byte Array) version is provided in .SSLServerCertEncodedB.

This property is read-only and not available at design time.

Data Type

Binary String

UseTCP Property (SysLog Control)

Whether to use TCP.

Syntax

syslogcontrol.UseTCP[=boolean]

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

Data Type

Boolean

Activate Method (SysLog Control)

Enables sending and receiving of data.

Syntax

syslogcontrol.Activate 

Remarks

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

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

Config Method (SysLog Control)

Sets or retrieves a configuration setting.

Syntax

syslogcontrol.Config ConfigurationString

Remarks

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

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

Disables sending and receive of data.

Syntax

syslogcontrol.Deactivate 

Remarks

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

DoEvents Method (SysLog Control)

Processes events from the internal message queue.

Syntax

syslogcontrol.DoEvents 

Remarks

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

Reset Method (SysLog Control)

Reset the control.

Syntax

syslogcontrol.Reset 

Remarks

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

ResolveRemoteHost Method (SysLog Control)

Resolves the hostname in RemoteHost to an IP address.

Syntax

syslogcontrol.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 control will resolve the hostname automatically when necessary. If DelayHostResolution is this method may be called to manually resolve RemoteHost if desired.

SendPacket Method (SysLog Control)

Send a log packet to RemoteHost .

Syntax

syslogcontrol.SendPacket Facility, Severity, Message

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 control. The third section is the Message itself.

Connected Event (SysLog Control)

Fired immediately after a connection completes (or fails).

Syntax

Sub syslogcontrol_Connected(RemoteAddress As String, RemotePort As Integer, StatusCode As Integer, Description As String)

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 Control)

Fired to indicate changes in a connection state.

Syntax

Sub syslogcontrol_ConnectionStatus(ConnectionEvent As String, StatusCode As Integer, Description As String)

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. The corresponding Visual Basic error code can be obtained by adding 15001 to this value.

Disconnected Event (SysLog Control)

Fired when a connection is closed.

Syntax

Sub syslogcontrol_Disconnected(RemoteAddress As String, RemotePort As Integer, StatusCode As Integer, Description As String)

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 Control)

Fired when information is available about errors during data delivery.

Syntax

Sub syslogcontrol_Error(ErrorCode As Integer, Description As String)

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the control fails with an error.

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 Control)

Fires whenever a system log packet is received.

Syntax

Sub syslogcontrol_PacketIn(FacilityCode As Integer, Facility As String, SeverityCode As Integer, Severity As String, Timestamp As String, Hostname As String, Message As String, Conforms As Boolean, Packet As String, SourceAddress As String, SourcePort As Integer)

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 control will search for the Timestamp and verify that it conforms. If it conforms, the control 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 Control)

Fired when the client presents its credentials to the server.

Syntax

Sub syslogcontrol_SSLClientAuthentication(RemoteAddress As String, RemotePort As Integer, CertEncoded As String, CertSubject As String, CertIssuer As String, Status As String, Accept As Boolean)

Remarks

This event fires when a client connects to the control 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 Control)

Fires when connecting to the server.

Syntax

Sub syslogcontrol_SSLServerAuthentication(RemoteAddress As String, RemotePort As Integer, CertEncoded As String, CertSubject As String, CertIssuer As String, Status As String, Accept As Boolean)

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 Control)

Shows the progress of the secure connection.

Syntax

Sub syslogcontrol_SSLStatus(RemoteAddress As String, RemotePort As Integer, Message As String)

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 Control)

The control 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 control, 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 Control)

SysLog Errors

	20452    Unable to acquire valid system time.

UDP Errors

	20105    UDP is already Active.
	20107    You cannot change the LocalPort while the control is Active.
	20108    You cannot change the LocalHost at this time. A connection is in progress.
	20110    The control must be Active for this operation.
	20113    Cannot change MaxPacketSize while the control is Active.
	20114    Cannot change ShareLocalPort option while the control is Active.
	20115    Cannot change RemoteHost when UseConnection is set and the control Active.
	20116    Cannot change RemotePort when UseConnection is set and the control is Active.
	20117    RemotePort can't be zero when UseConnection is set. Please specify a valid service port number.
	20118    Cannot change UseConnection while the control is Active.
	20119    Message can't be longer than MaxPacketSize.
	20120    Message too short.
	20435    Unable to convert string to selected CodePage

SSL Errors

	20271    Cannot load specified security library.
	20272    Cannot open certificate store.
	20273    Cannot find specified certificate.
	20274    Cannot acquire security credentials.
	20275    Cannot find certificate chain.
	20276    Cannot verify certificate chain.
	20277    Error during handshake.
	20281    Error verifying certificate.
	20282    Could not find client certificate.
	20283    Could not find server certificate.
	20284    Error encrypting data.
	20285    Error decrypting data.

TCP/IP Errors

	25005    [10004] Interrupted system call.
	25010    [10009] Bad file number.
	25014    [10013] Access denied.
	25015    [10014] Bad address.
	25023    [10022] Invalid argument.
	25025    [10024] Too many open files.
	25036    [10035] Operation would block.
	25037    [10036] Operation now in progress.
	25038    [10037] Operation already in progress.
	25039    [10038] Socket operation on non-socket.
	25040    [10039] Destination address required.
	25041    [10040] Message too long.
	25042    [10041] Protocol wrong type for socket.
	25043    [10042] Bad protocol option.
	25044    [10043] Protocol not supported.
	25045    [10044] Socket type not supported.
	25046    [10045] Operation not supported on socket.
	25047    [10046] Protocol family not supported.
	25048    [10047] Address family not supported by protocol family.
	25049    [10048] Address already in use.
	25050    [10049] Can't assign requested address.
	25051    [10050] Network is down.
	25052    [10051] Network is unreachable.
	25053    [10052] Net dropped connection or reset.
	25054    [10053] Software caused connection abort.
	25055    [10054] Connection reset by peer.
	25056    [10055] No buffer space available.
	25057    [10056] Socket is already connected.
	25058    [10057] Socket is not connected.
	25059    [10058] Can't send after socket shutdown.
	25060    [10059] Too many references, can't splice.
	25061    [10060] Connection timed out.
	25062    [10061] Connection refused.
	25063    [10062] Too many levels of symbolic links.
	25064    [10063] File name too long.
	25065    [10064] Host is down.
	25066    [10065] No route to host.
	25067    [10066] Directory not empty
	25068    [10067] Too many processes.
	25069    [10068] Too many users.
	25070    [10069] Disc Quota Exceeded.
	25071    [10070] Stale NFS file handle.
	25072    [10071] Too many levels of remote in path.
	25092    [10091] Network subsystem is unavailable.
	25093    [10092] WINSOCK DLL Version out of range.
	25094    [10093] Winsock not loaded yet.
	26002    [11001] Host not found.
	26003    [11002] Non-authoritative 'Host not found' (try again or check DNS setup).
	26004    [11003] Non-recoverable errors: FORMERR, REFUSED, NOTIMP.
	26005    [11004] Valid name, no data record (check DNS setup).