HardwareInfoDxe.c

/*/@file
  Hardware info parsing functions.
  Binary data is expected as a consecutive series of header - object pairs.
  Complete library providing list-like interface to dynamically manipulate
  hardware info objects and parsing from a generic blob.
 
  Copyright 2021 - 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
  SPDX-License-Identifier: BSD-2-Clause-Patent
 
**/
 
#include <Uefi/UefiBaseType.h>
#include <Uefi/UefiSpec.h>
#include <Library/DebugLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/BaseLib.h>
#include <Library/UefiLib.h>
 
#include <Library/HardwareInfoLib.h>
 
EFI_STATUS
CreateHardwareInfoList (
  IN  UINT8               *Blob,
  IN  UINTN               BlobSize,
  IN  HARDWARE_INFO_TYPE  TypeFilter,
  OUT LIST_ENTRY          *ListHead
  )
{
  UINT8          *Index;
  UINT8          *BlobEnd;
  HARDWARE_INFO  *HwComponent;
 
  if ((Blob == NULL) || (BlobSize <= 0) ||
      (ListHead == NULL))
  {
    return EFI_INVALID_PARAMETER;
  }
 
  Index   = Blob;
  BlobEnd = Blob + BlobSize;
  while (Index < BlobEnd) {
    HwComponent = AllocateZeroPool (sizeof (HARDWARE_INFO));
 
    if (HwComponent == NULL) {
      goto FailedAllocate;
    }
 
    HwComponent->Header.Type.Uint64 = *((UINT64 *)Index);
    Index                          += sizeof (HwComponent->Header.Type);
    HwComponent->Header.Size        = *((UINT64 *)(Index));
    Index                          += sizeof (HwComponent->Header.Size);
 
    if ((HwComponent->Header.Size > MAX_UINTN) || (Index < Blob) || ((Index + HwComponent->Header.Size) > BlobEnd)) {
      goto FreeResources;
    }
 
    //
    // Check if optional TypeFilter is set, skip if the current
    // object is of a different type and release the partially
    // allocated object
    //
    if ((TypeFilter != HardwareInfoTypeUndefined) &&
        (HwComponent->Header.Type.Value != TypeFilter))
    {
      FreePool (HwComponent);
      Index += HwComponent->Header.Size;
      continue;
    }
 
    HwComponent->Data.Raw = AllocateZeroPool ((UINTN)HwComponent->Header.Size);
    if (HwComponent->Data.Raw == NULL) {
      goto FreeResources;
    }
 
    CopyMem (HwComponent->Data.Raw, Index, (UINTN)HwComponent->Header.Size);
    Index += HwComponent->Header.Size;
 
    InsertTailList (ListHead, &HwComponent->Link);
  }
 
  return EFI_SUCCESS;
 
FreeResources:
  //
  // Clean the resources allocated in the incomplete cycle
  //
  FreePool (HwComponent);
 
FailedAllocate:
  DEBUG ((
    DEBUG_ERROR,
    "%a: Failed to allocate memory for hardware info\n",
    __func__
    ));
 
  return EFI_OUT_OF_RESOURCES;
}
 
VOID
FreeHardwareInfoList (
  IN OUT  LIST_ENTRY  *ListHead
  )
{
  LIST_ENTRY     *CurrentLink;
  HARDWARE_INFO  *HwComponent;
 
  if (IsListEmpty (ListHead)) {
    return;
  }
 
  CurrentLink = ListHead->ForwardLink;
  while (CurrentLink != NULL && CurrentLink != ListHead) {
    HwComponent = HARDWARE_INFO_FROM_LINK (CurrentLink);
 
    //
    // Remove item from list before invalidating the pointers
    //
    CurrentLink = RemoveEntryList (CurrentLink);
 
    FreePool (HwComponent->Data.Raw);
    FreePool (HwComponent);
  }
}