Handle external access to data model and access control

Typedefs
typedef MmsDataAccessError(*	WriteAccessHandler) (DataAttribute *dataAttribute, MmsValue *value, ClientConnection connection, void *parameter)
	callback handler to intercept/control client access to data attributes More...

Enumerations
enum	AccessPolicy { ACCESS_POLICY_ALLOW, ACCESS_POLICY_DENY }

Functions
void	IedServer_handleWriteAccess (IedServer self, DataAttribute *dataAttribute, WriteAccessHandler handler, void *parameter)
	Install a WriteAccessHandler for a data attribute. More...
void	IedServer_setWriteAccessPolicy (IedServer self, FunctionalConstraint fc, AccessPolicy policy)
	Change the default write access policy for functional constraint data with a specific FC. More...

Detailed Description

Typedef Documentation

typedef MmsDataAccessError(* WriteAccessHandler) (DataAttribute *dataAttribute, MmsValue *value, ClientConnection connection, void *parameter)

callback handler to intercept/control client access to data attributes

User provided callback function to intercept/control MMS client access to IEC 61850 data attributes. The application can install the same handler multiple times and distinguish data attributes by the dataAttribute parameter. This handler can be used to perform write access control do data attributes. One application can be to allow write access only from a specific client. Another application could be to check if the value is in the allowed range before the write is accepted.

Parameters

the	data attribute that has been written by an MMS client.
the	value the client want to write to the data attribute
connection	the connection object of the client connection that invoked the write operation
parameter	the user provided parameter

Returns

true if access is accepted, false if access is denied.

Enumeration Type Documentation

enum AccessPolicy

Enumerator
ACCESS_POLICY_ALLOW
ACCESS_POLICY_DENY

Function Documentation

void IedServer_handleWriteAccess	(	IedServer	self,
		DataAttribute *	dataAttribute,
		WriteAccessHandler	handler,
		void *	parameter
	)

Install a WriteAccessHandler for a data attribute.

This instructs the server to monitor write attempts by MMS clients to specific data attributes. If a client tries to write to the monitored data attribute the handler is invoked. The handler can decide if the write access will be allowed or denied. If a WriteAccessHandler is set for a specific data attribute - the default write access policy will not be performed for that data attribute.

Parameters

self	the instance of IedServer to operate on.
dataAttribute	the data attribute to monitor
handler	the callback function that is invoked if a client tries to write to the monitored data attribute.
parameter	a user provided parameter that is passed to the WriteAccessHandler when called.

void IedServer_setWriteAccessPolicy	(	IedServer	self,
		FunctionalConstraint	fc,
		AccessPolicy	policy
	)

Change the default write access policy for functional constraint data with a specific FC.

Parameters

self	the instance of IedServer to operate on.
fc	the FC for which to change the default write access policy.
policy	the new policy to apply.