system76-edk2/MdeModulePkg/Universal/Variable/RuntimeDxe/VarCheck.c

/** @file
  Implementation functions and structures for var check protocol
  and variable lock protocol based on VarCheckLib.

Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution.  The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php

THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#include "Variable.h"

/**
  Mark a variable that will become read-only after leaving the DXE phase of execution.
  Write request coming from SMM environment through EFI_SMM_VARIABLE_PROTOCOL is allowed.

  @param[in] This          The VARIABLE_LOCK_PROTOCOL instance.
  @param[in] VariableName  A pointer to the variable name that will be made read-only subsequently.
  @param[in] VendorGuid    A pointer to the vendor GUID that will be made read-only subsequently.

  @retval EFI_SUCCESS           The variable specified by the VariableName and the VendorGuid was marked
                                as pending to be read-only.
  @retval EFI_INVALID_PARAMETER VariableName or VendorGuid is NULL.
                                Or VariableName is an empty string.
  @retval EFI_ACCESS_DENIED     EFI_END_OF_DXE_EVENT_GROUP_GUID or EFI_EVENT_GROUP_READY_TO_BOOT has
                                already been signaled.
  @retval EFI_OUT_OF_RESOURCES  There is not enough resource to hold the lock request.
**/
EFI_STATUS
EFIAPI
VariableLockRequestToLock (
  IN CONST EDKII_VARIABLE_LOCK_PROTOCOL *This,
  IN       CHAR16                       *VariableName,
  IN       EFI_GUID                     *VendorGuid
  )
{
  EFI_STATUS                    Status;
  VAR_CHECK_VARIABLE_PROPERTY   Property;

  AcquireLockOnlyAtBootTime (&mVariableModuleGlobal->VariableGlobal.VariableServicesLock);

  Status = VarCheckLibVariablePropertyGet (VariableName, VendorGuid, &Property);
  if (!EFI_ERROR (Status)) {
    Property.Property |= VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY;
  } else {
    Property.Revision = VAR_CHECK_VARIABLE_PROPERTY_REVISION;
    Property.Property = VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY;
    Property.Attributes = 0;
    Property.MinSize = 1;
    Property.MaxSize = MAX_UINTN;
  }
  Status = VarCheckLibVariablePropertySet (VariableName, VendorGuid, &Property);

  DEBUG ((EFI_D_INFO, "[Variable] Lock: %g:%s %r\n", VendorGuid, VariableName, Status));

  ReleaseLockOnlyAtBootTime (&mVariableModuleGlobal->VariableGlobal.VariableServicesLock);

  return Status;
}

/**
  Register SetVariable check handler.

  @param[in] Handler            Pointer to check handler.

  @retval EFI_SUCCESS           The SetVariable check handler was registered successfully.
  @retval EFI_INVALID_PARAMETER Handler is NULL.
  @retval EFI_ACCESS_DENIED     EFI_END_OF_DXE_EVENT_GROUP_GUID or EFI_EVENT_GROUP_READY_TO_BOOT has
                                already been signaled.
  @retval EFI_OUT_OF_RESOURCES  There is not enough resource for the SetVariable check handler register request.
  @retval EFI_UNSUPPORTED       This interface is not implemented.
                                For example, it is unsupported in VarCheck protocol if both VarCheck and SmmVarCheck protocols are present.

**/
EFI_STATUS
EFIAPI
VarCheckRegisterSetVariableCheckHandler (
  IN VAR_CHECK_SET_VARIABLE_CHECK_HANDLER   Handler
  )
{
  EFI_STATUS    Status;

  AcquireLockOnlyAtBootTime (&mVariableModuleGlobal->VariableGlobal.VariableServicesLock);
  Status = VarCheckLibRegisterSetVariableCheckHandler (Handler);
  ReleaseLockOnlyAtBootTime (&mVariableModuleGlobal->VariableGlobal.VariableServicesLock);

  return Status;
}

/**
  Variable property set.

  @param[in] Name               Pointer to the variable name.
  @param[in] Guid               Pointer to the vendor GUID.
  @param[in] VariableProperty   Pointer to the input variable property.

  @retval EFI_SUCCESS           The property of variable specified by the Name and Guid was set successfully.
  @retval EFI_INVALID_PARAMETER Name, Guid or VariableProperty is NULL, or Name is an empty string,
                                or the fields of VariableProperty are not valid.
  @retval EFI_ACCESS_DENIED     EFI_END_OF_DXE_EVENT_GROUP_GUID or EFI_EVENT_GROUP_READY_TO_BOOT has
                                already been signaled.
  @retval EFI_OUT_OF_RESOURCES  There is not enough resource for the variable property set request.

**/
EFI_STATUS
EFIAPI
VarCheckVariablePropertySet (
  IN CHAR16                         *Name,
  IN EFI_GUID                       *Guid,
  IN VAR_CHECK_VARIABLE_PROPERTY    *VariableProperty
  )
{
  EFI_STATUS    Status;

  AcquireLockOnlyAtBootTime (&mVariableModuleGlobal->VariableGlobal.VariableServicesLock);
  Status = VarCheckLibVariablePropertySet (Name, Guid, VariableProperty);
  ReleaseLockOnlyAtBootTime (&mVariableModuleGlobal->VariableGlobal.VariableServicesLock);

  return Status;
}

/**
  Variable property get.

  @param[in]  Name              Pointer to the variable name.
  @param[in]  Guid              Pointer to the vendor GUID.
  @param[out] VariableProperty  Pointer to the output variable property.

  @retval EFI_SUCCESS           The property of variable specified by the Name and Guid was got successfully.
  @retval EFI_INVALID_PARAMETER Name, Guid or VariableProperty is NULL, or Name is an empty string.
  @retval EFI_NOT_FOUND         The property of variable specified by the Name and Guid was not found.

**/
EFI_STATUS
EFIAPI
VarCheckVariablePropertyGet (
  IN CHAR16                         *Name,
  IN EFI_GUID                       *Guid,
  OUT VAR_CHECK_VARIABLE_PROPERTY   *VariableProperty
  )
{
  EFI_STATUS    Status;

  AcquireLockOnlyAtBootTime (&mVariableModuleGlobal->VariableGlobal.VariableServicesLock);
  Status = VarCheckLibVariablePropertyGet (Name, Guid, VariableProperty);
  ReleaseLockOnlyAtBootTime (&mVariableModuleGlobal->VariableGlobal.VariableServicesLock);

  return Status;
}