UefiDevicePathLib.c

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#include <Uefi.h>
 
#include <Protocol/DevicePathUtilities.h>
#include <Protocol/DevicePathToText.h>
#include <Protocol/DevicePathFromText.h>
 
#include <Library/DevicePathLib.h>
#include <Library/DebugLib.h>
#include <Library/BaseLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/PcdLib.h>
 
GLOBAL_REMOVE_IF_UNREFERENCED EFI_DEVICE_PATH_UTILITIES_PROTOCOL  *mDevicePathLibDevicePathUtilities = NULL;
GLOBAL_REMOVE_IF_UNREFERENCED EFI_DEVICE_PATH_TO_TEXT_PROTOCOL    *mDevicePathLibDevicePathToText    = NULL;
GLOBAL_REMOVE_IF_UNREFERENCED EFI_DEVICE_PATH_FROM_TEXT_PROTOCOL  *mDevicePathLibDevicePathFromText  = NULL;
 
//
// Template for an end-of-device path node.
//
GLOBAL_REMOVE_IF_UNREFERENCED CONST EFI_DEVICE_PATH_PROTOCOL  mUefiDevicePathLibEndDevicePath = {
  END_DEVICE_PATH_TYPE,
  END_ENTIRE_DEVICE_PATH_SUBTYPE,
  {
    END_DEVICE_PATH_LENGTH,
    0
  }
};
 
EFI_STATUS
EFIAPI
DevicePathLibConstructor (
  IN      EFI_HANDLE        ImageHandle,
  IN      EFI_SYSTEM_TABLE  *SystemTable
  )
{
  EFI_STATUS  Status;
 
  Status = gBS->LocateProtocol (
                  &gEfiDevicePathUtilitiesProtocolGuid,
                  NULL,
                  (VOID **)&mDevicePathLibDevicePathUtilities
                  );
  ASSERT_EFI_ERROR (Status);
  ASSERT (mDevicePathLibDevicePathUtilities != NULL);
  return Status;
}
 
BOOLEAN
EFIAPI
IsDevicePathValid (
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath,
  IN       UINTN                     MaxSize
  )
{
  UINTN  Count;
  UINTN  Size;
  UINTN  NodeLength;
 
  ASSERT (DevicePath != NULL);
 
  if (MaxSize == 0) {
    MaxSize = MAX_UINTN;
  }
 
  //
  // Validate the input size big enough to touch the first node.
  //
  if (MaxSize < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {
    return FALSE;
  }
 
  for (Count = 0, Size = 0; !IsDevicePathEnd (DevicePath); DevicePath = NextDevicePathNode (DevicePath)) {
    NodeLength = DevicePathNodeLength (DevicePath);
    if (NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {
      return FALSE;
    }
 
    if (NodeLength > MAX_UINTN - Size) {
      return FALSE;
    }
 
    Size += NodeLength;
 
    //
    // Validate next node before touch it.
    //
    if (Size > MaxSize - END_DEVICE_PATH_LENGTH ) {
      return FALSE;
    }
 
    if (PcdGet32 (PcdMaximumDevicePathNodeCount) > 0) {
      Count++;
      if (Count >= PcdGet32 (PcdMaximumDevicePathNodeCount)) {
        return FALSE;
      }
    }
 
    //
    // FilePath must be a NULL-terminated string.
    //
    if ((DevicePathType (DevicePath) == MEDIA_DEVICE_PATH) &&
        (DevicePathSubType (DevicePath) == MEDIA_FILEPATH_DP) &&
        (*(CHAR16 *)((UINT8 *)DevicePath + NodeLength - 2) != 0))
    {
      return FALSE;
    }
  }
 
  //
  // Only return TRUE when the End Device Path node is valid.
  //
  return (BOOLEAN)(DevicePathNodeLength (DevicePath) == END_DEVICE_PATH_LENGTH);
}
 
UINT8
EFIAPI
DevicePathType (
  IN CONST VOID  *Node
  )
{
  ASSERT (Node != NULL);
  return ((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Type;
}
 
UINT8
EFIAPI
DevicePathSubType (
  IN CONST VOID  *Node
  )
{
  ASSERT (Node != NULL);
  return ((EFI_DEVICE_PATH_PROTOCOL *)(Node))->SubType;
}
 
UINTN
EFIAPI
DevicePathNodeLength (
  IN CONST VOID  *Node
  )
{
  ASSERT (Node != NULL);
  return ReadUnaligned16 ((UINT16 *)&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0]);
}
 
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
NextDevicePathNode (
  IN CONST VOID  *Node
  )
{
  ASSERT (Node != NULL);
  return (EFI_DEVICE_PATH_PROTOCOL *)((UINT8 *)(Node) + DevicePathNodeLength (Node));
}
 
BOOLEAN
EFIAPI
IsDevicePathEndType (
  IN CONST VOID  *Node
  )
{
  ASSERT (Node != NULL);
  return (BOOLEAN)(DevicePathType (Node) == END_DEVICE_PATH_TYPE);
}
 
BOOLEAN
EFIAPI
IsDevicePathEnd (
  IN CONST VOID  *Node
  )
{
  ASSERT (Node != NULL);
  return (BOOLEAN)(IsDevicePathEndType (Node) && DevicePathSubType (Node) == END_ENTIRE_DEVICE_PATH_SUBTYPE);
}
 
BOOLEAN
EFIAPI
IsDevicePathEndInstance (
  IN CONST VOID  *Node
  )
{
  ASSERT (Node != NULL);
  return (BOOLEAN)(IsDevicePathEndType (Node) && DevicePathSubType (Node) == END_INSTANCE_DEVICE_PATH_SUBTYPE);
}
 
UINT16
EFIAPI
SetDevicePathNodeLength (
  IN OUT VOID  *Node,
  IN UINTN     Length
  )
{
  ASSERT (Node != NULL);
  ASSERT ((Length >= sizeof (EFI_DEVICE_PATH_PROTOCOL)) && (Length < SIZE_64KB));
  return WriteUnaligned16 ((UINT16 *)&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0], (UINT16)(Length));
}
 
VOID
EFIAPI
SetDevicePathEndNode (
  OUT VOID  *Node
  )
{
  ASSERT (Node != NULL);
  CopyMem (Node, &mUefiDevicePathLibEndDevicePath, sizeof (mUefiDevicePathLibEndDevicePath));
}
 
UINTN
EFIAPI
GetDevicePathSize (
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath
  )
{
  return mDevicePathLibDevicePathUtilities->GetDevicePathSize (DevicePath);
}
 
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
DuplicateDevicePath (
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath
  )
{
  return mDevicePathLibDevicePathUtilities->DuplicateDevicePath (DevicePath);
}
 
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
AppendDevicePath (
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *FirstDevicePath   OPTIONAL,
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *SecondDevicePath  OPTIONAL
  )
{
  return mDevicePathLibDevicePathUtilities->AppendDevicePath (FirstDevicePath, SecondDevicePath);
}
 
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
AppendDevicePathNode (
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath      OPTIONAL,
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePathNode  OPTIONAL
  )
{
  return mDevicePathLibDevicePathUtilities->AppendDeviceNode (DevicePath, DevicePathNode);
}
 
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
AppendDevicePathInstance (
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath         OPTIONAL,
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePathInstance OPTIONAL
  )
{
  return mDevicePathLibDevicePathUtilities->AppendDevicePathInstance (DevicePath, DevicePathInstance);
}
 
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
GetNextDevicePathInstance (
  IN OUT EFI_DEVICE_PATH_PROTOCOL  **DevicePath,
  OUT UINTN                        *Size
  )
{
  ASSERT (Size != NULL);
  return mDevicePathLibDevicePathUtilities->GetNextDevicePathInstance (DevicePath, Size);
}
 
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
CreateDeviceNode (
  IN UINT8   NodeType,
  IN UINT8   NodeSubType,
  IN UINT16  NodeLength
  )
{
  return mDevicePathLibDevicePathUtilities->CreateDeviceNode (NodeType, NodeSubType, NodeLength);
}
 
BOOLEAN
EFIAPI
IsDevicePathMultiInstance (
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath
  )
{
  return mDevicePathLibDevicePathUtilities->IsDevicePathMultiInstance (DevicePath);
}
 
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
DevicePathFromHandle (
  IN EFI_HANDLE  Handle
  )
{
  EFI_DEVICE_PATH_PROTOCOL  *DevicePath;
  EFI_STATUS                Status;
 
  Status = gBS->HandleProtocol (
                  Handle,
                  &gEfiDevicePathProtocolGuid,
                  (VOID *)&DevicePath
                  );
  if (EFI_ERROR (Status)) {
    DevicePath = NULL;
  }
 
  return DevicePath;
}
 
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
FileDevicePath (
  IN EFI_HANDLE    Device      OPTIONAL,
  IN CONST CHAR16  *FileName
  )
{
  UINTN                     Size;
  FILEPATH_DEVICE_PATH      *FilePath;
  EFI_DEVICE_PATH_PROTOCOL  *DevicePath;
  EFI_DEVICE_PATH_PROTOCOL  *FileDevicePath;
 
  DevicePath = NULL;
 
  Size           = StrSize (FileName);
  FileDevicePath = AllocatePool (Size + SIZE_OF_FILEPATH_DEVICE_PATH + END_DEVICE_PATH_LENGTH);
  if (FileDevicePath != NULL) {
    FilePath                 = (FILEPATH_DEVICE_PATH *)FileDevicePath;
    FilePath->Header.Type    = MEDIA_DEVICE_PATH;
    FilePath->Header.SubType = MEDIA_FILEPATH_DP;
    CopyMem (&FilePath->PathName, FileName, Size);
    SetDevicePathNodeLength (&FilePath->Header, Size + SIZE_OF_FILEPATH_DEVICE_PATH);
    SetDevicePathEndNode (NextDevicePathNode (&FilePath->Header));
 
    if (Device != NULL) {
      DevicePath = DevicePathFromHandle (Device);
    }
 
    DevicePath = AppendDevicePath (DevicePath, FileDevicePath);
    FreePool (FileDevicePath);
  }
 
  return DevicePath;
}
 
VOID *
UefiDevicePathLibLocateProtocol (
  EFI_GUID  *ProtocolGuid
  )
{
  EFI_STATUS  Status;
  VOID        *Protocol;
 
  Status = gBS->LocateProtocol (
                  ProtocolGuid,
                  NULL,
                  (VOID **)&Protocol
                  );
  if (EFI_ERROR (Status)) {
    return NULL;
  } else {
    return Protocol;
  }
}
 
CHAR16 *
EFIAPI
ConvertDeviceNodeToText (
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DeviceNode,
  IN BOOLEAN                         DisplayOnly,
  IN BOOLEAN                         AllowShortcuts
  )
{
  if (mDevicePathLibDevicePathToText == NULL) {
    mDevicePathLibDevicePathToText = UefiDevicePathLibLocateProtocol (&gEfiDevicePathToTextProtocolGuid);
  }
 
  if (mDevicePathLibDevicePathToText != NULL) {
    return mDevicePathLibDevicePathToText->ConvertDeviceNodeToText (DeviceNode, DisplayOnly, AllowShortcuts);
  } else {
    return NULL;
  }
}
 
CHAR16 *
EFIAPI
ConvertDevicePathToText (
  IN CONST EFI_DEVICE_PATH_PROTOCOL  *DevicePath,
  IN BOOLEAN                         DisplayOnly,
  IN BOOLEAN                         AllowShortcuts
  )
{
  if (mDevicePathLibDevicePathToText == NULL) {
    mDevicePathLibDevicePathToText = UefiDevicePathLibLocateProtocol (&gEfiDevicePathToTextProtocolGuid);
  }
 
  if (mDevicePathLibDevicePathToText != NULL) {
    return mDevicePathLibDevicePathToText->ConvertDevicePathToText (DevicePath, DisplayOnly, AllowShortcuts);
  } else {
    return NULL;
  }
}
 
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
ConvertTextToDeviceNode (
  IN CONST CHAR16  *TextDeviceNode
  )
{
  if (mDevicePathLibDevicePathFromText == NULL) {
    mDevicePathLibDevicePathFromText = UefiDevicePathLibLocateProtocol (&gEfiDevicePathFromTextProtocolGuid);
  }
 
  if (mDevicePathLibDevicePathFromText != NULL) {
    return mDevicePathLibDevicePathFromText->ConvertTextToDeviceNode (TextDeviceNode);
  } else {
    return NULL;
  }
}
 
EFI_DEVICE_PATH_PROTOCOL *
EFIAPI
ConvertTextToDevicePath (
  IN CONST CHAR16  *TextDevicePath
  )
{
  if (mDevicePathLibDevicePathFromText == NULL) {
    mDevicePathLibDevicePathFromText = UefiDevicePathLibLocateProtocol (&gEfiDevicePathFromTextProtocolGuid);
  }
 
  if (mDevicePathLibDevicePathFromText != NULL) {
    return mDevicePathLibDevicePathFromText->ConvertTextToDevicePath (TextDevicePath);
  } else {
    return NULL;
  }
}