VariablePolicyLib.h File Reference

Functions
EFI_STATUS EFIAPI	RegisterVariablePolicy (IN CONST VARIABLE_POLICY_ENTRY *NewPolicy)
EFI_STATUS EFIAPI	ValidateSetVariable (IN CHAR16 *VariableName, IN EFI_GUID *VendorGuid, IN UINT32 Attributes, IN UINTN DataSize, IN VOID *Data)
EFI_STATUS EFIAPI	DisableVariablePolicy (VOID)
EFI_STATUS EFIAPI	DumpVariablePolicy (OUT UINT8 *Policy, IN OUT UINT32 *Size)
BOOLEAN EFIAPI	IsVariablePolicyEnabled (VOID)
EFI_STATUS EFIAPI	LockVariablePolicy (VOID)
BOOLEAN EFIAPI	IsVariablePolicyInterfaceLocked (VOID)
EFI_STATUS EFIAPI	InitVariablePolicyLib (IN EFI_GET_VARIABLE GetVariableHelper)
BOOLEAN EFIAPI	IsVariablePolicyLibInitialized (VOID)
EFI_STATUS EFIAPI	DeinitVariablePolicyLib (VOID)

Function Documentation

EFI_STATUS EFIAPI DeinitVariablePolicyLib

(

VOID

)

This helper function tears down the library.

Should generally only be used for test harnesses.

Return values

EFI_SUCCESS
EFI_NOT_READY	Deinitialize was called without first calling initialize.

EFI_STATUS EFIAPI DisableVariablePolicy

(

VOID

)

This API function disables the variable policy enforcement. If it's already been called once, will return EFI_ALREADY_STARTED.

Return values

EFI_SUCCESS
EFI_ALREADY_STARTED	Has already been called once this boot.
EFI_WRITE_PROTECTED	Interface has been locked until reboot.
EFI_WRITE_PROTECTED	Interface option is disabled by platform PCD.
EFI_NOT_READY	Library has not yet been initialized.

EFI_STATUS EFIAPI DumpVariablePolicy	(	OUT UINT8 *	Policy,
		IN OUT UINT32 *	Size
	)

This API function will dump the entire contents of the variable policy table.

Similar to GetVariable, the first call can be made with a 0 size and it will return the size of the buffer required to hold the entire table.

Parameters

[out]	Policy	Pointer to the policy buffer. Can be NULL if Size is 0.
[in,out]	Size	On input, the size of the output buffer. On output, the size of the data returned.

Return values

EFI_SUCCESS	Policy data is in the output buffer and Size has been updated.
EFI_INVALID_PARAMETER	Size is NULL, or Size is non-zero and Policy is NULL.
EFI_BUFFER_TOO_SMALL	Size is insufficient to hold policy. Size updated with required size.
EFI_NOT_READY	Library has not yet been initialized.

EFI_STATUS EFIAPI InitVariablePolicyLib

(

IN EFI_GET_VARIABLE

GetVariableHelper

)

This helper function initializes the library and sets up any required internal structures or handlers.

Also registers the internal pointer for the GetVariable helper.

Parameters

[in]

GetVariableHelper

A function pointer matching the EFI_GET_VARIABLE prototype that will be used to check policy criteria that involve the existence of other variables.

Return values

EFI_SUCCESS
EFI_ALREADY_STARTED	The initialize function has been called more than once without a call to deinitialize.

BOOLEAN EFIAPI IsVariablePolicyEnabled

(

VOID

)

This API function returns whether or not the policy engine is currently being enforced.

Return values

TRUE
FALSE
FALSE	Library has not yet been initialized.

BOOLEAN EFIAPI IsVariablePolicyInterfaceLocked

(

VOID

)

This API function returns whether or not the policy interface is locked for the remainder of the boot.

Return values

TRUE
FALSE
FALSE	Library has not yet been initialized.

BOOLEAN EFIAPI IsVariablePolicyLibInitialized

(

VOID

)

This helper function returns whether or not the library is currently initialized.

Return values

TRUE
FALSE

EFI_STATUS EFIAPI LockVariablePolicy

(

VOID

)

This API function locks the interface so that no more policy updates can be performed or changes made to the enforcement until the next boot.

Return values

EFI_SUCCESS
EFI_NOT_READY	Library has not yet been initialized.

EFI_STATUS EFIAPI RegisterVariablePolicy

(

IN CONST VARIABLE_POLICY_ENTRY *

NewPolicy

)

This API function validates and registers a new policy with the policy enforcement engine.

Parameters

[in]

NewPolicy

Pointer to the incoming policy structure.

Return values

EFI_SUCCESS
EFI_INVALID_PARAMETER	NewPolicy is NULL or is internally inconsistent.
EFI_ALREADY_STARTED	An identical matching policy already exists.
EFI_WRITE_PROTECTED	The interface has been locked until the next reboot.
EFI_UNSUPPORTED	Policy enforcement has been disabled. No reason to add more policies.
EFI_ABORTED	A calculation error has prevented this function from completing.
EFI_OUT_OF_RESOURCES	Cannot grow the table to hold any more policies.
EFI_NOT_READY	Library has not yet been initialized.

EFI_STATUS EFIAPI ValidateSetVariable	(	IN CHAR16 *	VariableName,
		IN EFI_GUID *	VendorGuid,
		IN UINT32	Attributes,
		IN UINTN	DataSize,
		IN VOID *	Data
	)

This API function checks to see whether the parameters to SetVariable would be allowed according to the current variable policies.

Parameters

[in]	VariableName	Same as EFI_SET_VARIABLE.
[in]	VendorGuid	Same as EFI_SET_VARIABLE.
[in]	Attributes	Same as EFI_SET_VARIABLE.
[in]	DataSize	Same as EFI_SET_VARIABLE.
[in]	Data	Same as EFI_SET_VARIABLE.

Return values

EFI_SUCCESS	A matching policy allows this update.
EFI_SUCCESS	There are currently no policies that restrict this update.
EFI_SUCCESS	The protections have been disable until the next reboot.
EFI_WRITE_PROTECTED	Variable is currently locked.
EFI_INVALID_PARAMETER	Attributes or size are invalid.
EFI_ABORTED	A lock policy exists, but an error prevented evaluation.
EFI_NOT_READY	Library has not been initialized.