VariableParsing.c

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#include "VariableParsing.h"
 
BOOLEAN
IsValidVariableHeader (
  IN  VARIABLE_HEADER  *Variable,
  IN  VARIABLE_HEADER  *VariableStoreEnd
  )
{
  if ((Variable == NULL) || (Variable >= VariableStoreEnd) || (Variable->StartId != VARIABLE_DATA)) {
    //
    // Variable is NULL or has reached the end of variable store,
    // or the StartId is not correct.
    //
    return FALSE;
  }
 
  return TRUE;
}
 
VARIABLE_STORE_STATUS
GetVariableStoreStatus (
  IN VARIABLE_STORE_HEADER  *VarStoreHeader
  )
{
  if ((CompareGuid (&VarStoreHeader->Signature, &gEfiAuthenticatedVariableGuid) ||
       CompareGuid (&VarStoreHeader->Signature, &gEfiVariableGuid)) &&
      (VarStoreHeader->Format == VARIABLE_STORE_FORMATTED) &&
      (VarStoreHeader->State == VARIABLE_STORE_HEALTHY)
      )
  {
    return EfiValid;
  } else if ((((UINT32 *)(&VarStoreHeader->Signature))[0] == 0xffffffff) &&
             (((UINT32 *)(&VarStoreHeader->Signature))[1] == 0xffffffff) &&
             (((UINT32 *)(&VarStoreHeader->Signature))[2] == 0xffffffff) &&
             (((UINT32 *)(&VarStoreHeader->Signature))[3] == 0xffffffff) &&
             (VarStoreHeader->Size == 0xffffffff) &&
             (VarStoreHeader->Format == 0xff) &&
             (VarStoreHeader->State == 0xff)
             )
  {
    return EfiRaw;
  } else {
    return EfiInvalid;
  }
}
 
UINTN
GetVariableHeaderSize (
  IN  BOOLEAN  AuthFormat
  )
{
  UINTN  Value;
 
  if (AuthFormat) {
    Value = sizeof (AUTHENTICATED_VARIABLE_HEADER);
  } else {
    Value = sizeof (VARIABLE_HEADER);
  }
 
  return Value;
}
 
UINTN
NameSizeOfVariable (
  IN  VARIABLE_HEADER  *Variable,
  IN  BOOLEAN          AuthFormat
  )
{
  AUTHENTICATED_VARIABLE_HEADER  *AuthVariable;
 
  AuthVariable = (AUTHENTICATED_VARIABLE_HEADER *)Variable;
  if (AuthFormat) {
    if ((AuthVariable->State == (UINT8)(-1)) ||
        (AuthVariable->DataSize == (UINT32)(-1)) ||
        (AuthVariable->NameSize == (UINT32)(-1)) ||
        (AuthVariable->Attributes == (UINT32)(-1)))
    {
      return 0;
    }
 
    return (UINTN)AuthVariable->NameSize;
  } else {
    if ((Variable->State == (UINT8)(-1)) ||
        (Variable->DataSize == (UINT32)(-1)) ||
        (Variable->NameSize == (UINT32)(-1)) ||
        (Variable->Attributes == (UINT32)(-1)))
    {
      return 0;
    }
 
    return (UINTN)Variable->NameSize;
  }
}
 
VOID
SetNameSizeOfVariable (
  IN VARIABLE_HEADER  *Variable,
  IN UINTN            NameSize,
  IN BOOLEAN          AuthFormat
  )
{
  AUTHENTICATED_VARIABLE_HEADER  *AuthVariable;
 
  AuthVariable = (AUTHENTICATED_VARIABLE_HEADER *)Variable;
  if (AuthFormat) {
    AuthVariable->NameSize = (UINT32)NameSize;
  } else {
    Variable->NameSize = (UINT32)NameSize;
  }
}
 
UINTN
DataSizeOfVariable (
  IN  VARIABLE_HEADER  *Variable,
  IN  BOOLEAN          AuthFormat
  )
{
  AUTHENTICATED_VARIABLE_HEADER  *AuthVariable;
 
  AuthVariable = (AUTHENTICATED_VARIABLE_HEADER *)Variable;
  if (AuthFormat) {
    if ((AuthVariable->State == (UINT8)(-1)) ||
        (AuthVariable->DataSize == (UINT32)(-1)) ||
        (AuthVariable->NameSize == (UINT32)(-1)) ||
        (AuthVariable->Attributes == (UINT32)(-1)))
    {
      return 0;
    }
 
    return (UINTN)AuthVariable->DataSize;
  } else {
    if ((Variable->State == (UINT8)(-1)) ||
        (Variable->DataSize == (UINT32)(-1)) ||
        (Variable->NameSize == (UINT32)(-1)) ||
        (Variable->Attributes == (UINT32)(-1)))
    {
      return 0;
    }
 
    return (UINTN)Variable->DataSize;
  }
}
 
VOID
SetDataSizeOfVariable (
  IN  VARIABLE_HEADER  *Variable,
  IN  UINTN            DataSize,
  IN  BOOLEAN          AuthFormat
  )
{
  AUTHENTICATED_VARIABLE_HEADER  *AuthVariable;
 
  AuthVariable = (AUTHENTICATED_VARIABLE_HEADER *)Variable;
  if (AuthFormat) {
    AuthVariable->DataSize = (UINT32)DataSize;
  } else {
    Variable->DataSize = (UINT32)DataSize;
  }
}
 
CHAR16 *
GetVariableNamePtr (
  IN  VARIABLE_HEADER  *Variable,
  IN  BOOLEAN          AuthFormat
  )
{
  return (CHAR16 *)((UINTN)Variable + GetVariableHeaderSize (AuthFormat));
}
 
EFI_GUID *
GetVendorGuidPtr (
  IN  VARIABLE_HEADER  *Variable,
  IN  BOOLEAN          AuthFormat
  )
{
  AUTHENTICATED_VARIABLE_HEADER  *AuthVariable;
 
  AuthVariable = (AUTHENTICATED_VARIABLE_HEADER *)Variable;
  if (AuthFormat) {
    return &AuthVariable->VendorGuid;
  } else {
    return &Variable->VendorGuid;
  }
}
 
UINT8 *
GetVariableDataPtr (
  IN  VARIABLE_HEADER  *Variable,
  IN  BOOLEAN          AuthFormat
  )
{
  UINTN  Value;
 
  //
  // Be careful about pad size for alignment.
  //
  Value  =  (UINTN)GetVariableNamePtr (Variable, AuthFormat);
  Value += NameSizeOfVariable (Variable, AuthFormat);
  Value += GET_PAD_SIZE (NameSizeOfVariable (Variable, AuthFormat));
 
  return (UINT8 *)Value;
}
 
UINTN
GetVariableDataOffset (
  IN  VARIABLE_HEADER  *Variable,
  IN  BOOLEAN          AuthFormat
  )
{
  UINTN  Value;
 
  //
  // Be careful about pad size for alignment
  //
  Value  = GetVariableHeaderSize (AuthFormat);
  Value += NameSizeOfVariable (Variable, AuthFormat);
  Value += GET_PAD_SIZE (NameSizeOfVariable (Variable, AuthFormat));
 
  return Value;
}
 
VARIABLE_HEADER *
GetNextVariablePtr (
  IN  VARIABLE_HEADER  *Variable,
  IN  BOOLEAN          AuthFormat
  )
{
  UINTN  Value;
 
  Value  =  (UINTN)GetVariableDataPtr (Variable, AuthFormat);
  Value += DataSizeOfVariable (Variable, AuthFormat);
  Value += GET_PAD_SIZE (DataSizeOfVariable (Variable, AuthFormat));
 
  //
  // Be careful about pad size for alignment.
  //
  return (VARIABLE_HEADER *)HEADER_ALIGN (Value);
}
 
VARIABLE_HEADER *
GetStartPointer (
  IN VARIABLE_STORE_HEADER  *VarStoreHeader
  )
{
  //
  // The start of variable store.
  //
  return (VARIABLE_HEADER *)HEADER_ALIGN (VarStoreHeader + 1);
}
 
VARIABLE_HEADER *
GetEndPointer (
  IN VARIABLE_STORE_HEADER  *VarStoreHeader
  )
{
  //
  // The end of variable store
  //
  return (VARIABLE_HEADER *)HEADER_ALIGN ((UINTN)VarStoreHeader + VarStoreHeader->Size);
}
 
BOOLEAN
VariableCompareTimeStampInternal (
  IN EFI_TIME  *FirstTime,
  IN EFI_TIME  *SecondTime
  )
{
  if (FirstTime->Year != SecondTime->Year) {
    return (BOOLEAN)(FirstTime->Year < SecondTime->Year);
  } else if (FirstTime->Month != SecondTime->Month) {
    return (BOOLEAN)(FirstTime->Month < SecondTime->Month);
  } else if (FirstTime->Day != SecondTime->Day) {
    return (BOOLEAN)(FirstTime->Day < SecondTime->Day);
  } else if (FirstTime->Hour != SecondTime->Hour) {
    return (BOOLEAN)(FirstTime->Hour < SecondTime->Hour);
  } else if (FirstTime->Minute != SecondTime->Minute) {
    return (BOOLEAN)(FirstTime->Minute < SecondTime->Minute);
  }
 
  return (BOOLEAN)(FirstTime->Second <= SecondTime->Second);
}
 
EFI_STATUS
FindVariableEx (
  IN     CHAR16                  *VariableName,
  IN     EFI_GUID                *VendorGuid,
  IN     BOOLEAN                 IgnoreRtCheck,
  IN OUT VARIABLE_POINTER_TRACK  *PtrTrack,
  IN     BOOLEAN                 AuthFormat
  )
{
  VARIABLE_HEADER  *InDeletedVariable;
  VOID             *Point;
 
  PtrTrack->InDeletedTransitionPtr = NULL;
 
  //
  // Find the variable by walk through HOB, volatile and non-volatile variable store.
  //
  InDeletedVariable = NULL;
 
  for ( PtrTrack->CurrPtr = PtrTrack->StartPtr
        ; IsValidVariableHeader (PtrTrack->CurrPtr, PtrTrack->EndPtr)
        ; PtrTrack->CurrPtr = GetNextVariablePtr (PtrTrack->CurrPtr, AuthFormat)
        )
  {
    if ((PtrTrack->CurrPtr->State == VAR_ADDED) ||
        (PtrTrack->CurrPtr->State == (VAR_IN_DELETED_TRANSITION & VAR_ADDED))
        )
    {
      if (IgnoreRtCheck || !AtRuntime () || ((PtrTrack->CurrPtr->Attributes & EFI_VARIABLE_RUNTIME_ACCESS) != 0)) {
        if (VariableName[0] == 0) {
          if (PtrTrack->CurrPtr->State == (VAR_IN_DELETED_TRANSITION & VAR_ADDED)) {
            InDeletedVariable = PtrTrack->CurrPtr;
          } else {
            PtrTrack->InDeletedTransitionPtr = InDeletedVariable;
            return EFI_SUCCESS;
          }
        } else {
          if (CompareGuid (VendorGuid, GetVendorGuidPtr (PtrTrack->CurrPtr, AuthFormat))) {
            Point = (VOID *)GetVariableNamePtr (PtrTrack->CurrPtr, AuthFormat);
 
            ASSERT (NameSizeOfVariable (PtrTrack->CurrPtr, AuthFormat) != 0);
            if (CompareMem (VariableName, Point, NameSizeOfVariable (PtrTrack->CurrPtr, AuthFormat)) == 0) {
              if (PtrTrack->CurrPtr->State == (VAR_IN_DELETED_TRANSITION & VAR_ADDED)) {
                InDeletedVariable = PtrTrack->CurrPtr;
              } else {
                PtrTrack->InDeletedTransitionPtr = InDeletedVariable;
                return EFI_SUCCESS;
              }
            }
          }
        }
      }
    }
  }
 
  PtrTrack->CurrPtr = InDeletedVariable;
  return (PtrTrack->CurrPtr  == NULL) ? EFI_NOT_FOUND : EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
VariableServiceGetNextVariableInternal (
  IN  CHAR16                 *VariableName,
  IN  EFI_GUID               *VendorGuid,
  IN  VARIABLE_STORE_HEADER  **VariableStoreList,
  OUT VARIABLE_HEADER        **VariablePtr,
  IN  BOOLEAN                AuthFormat
  )
{
  EFI_STATUS              Status;
  VARIABLE_STORE_TYPE     StoreType;
  VARIABLE_POINTER_TRACK  Variable;
  VARIABLE_POINTER_TRACK  VariableInHob;
  VARIABLE_POINTER_TRACK  VariablePtrTrack;
 
  Status = EFI_NOT_FOUND;
 
  if (VariableStoreList == NULL) {
    return EFI_INVALID_PARAMETER;
  }
 
  ZeroMem (&Variable, sizeof (Variable));
 
  // Check if the variable exists in the given variable store list
  for (StoreType = (VARIABLE_STORE_TYPE)0; StoreType < VariableStoreTypeMax; StoreType++) {
    if (VariableStoreList[StoreType] == NULL) {
      continue;
    }
 
    Variable.StartPtr = GetStartPointer (VariableStoreList[StoreType]);
    Variable.EndPtr   = GetEndPointer (VariableStoreList[StoreType]);
    Variable.Volatile = (BOOLEAN)(StoreType == VariableStoreTypeVolatile);
 
    Status = FindVariableEx (VariableName, VendorGuid, FALSE, &Variable, AuthFormat);
    if (!EFI_ERROR (Status)) {
      break;
    }
  }
 
  if ((Variable.CurrPtr == NULL) || EFI_ERROR (Status)) {
    //
    // For VariableName is an empty string, FindVariableEx() will try to find and return
    // the first qualified variable, and if FindVariableEx() returns error (EFI_NOT_FOUND)
    // as no any variable is found, still go to return the error (EFI_NOT_FOUND).
    //
    if (VariableName[0] != 0) {
      //
      // For VariableName is not an empty string, and FindVariableEx() returns error as
      // VariableName and VendorGuid are not a name and GUID of an existing variable,
      // there is no way to get next variable, follow spec to return EFI_INVALID_PARAMETER.
      //
      Status = EFI_INVALID_PARAMETER;
    }
 
    goto Done;
  }
 
  if (VariableName[0] != 0) {
    //
    // If variable name is not empty, get next variable.
    //
    Variable.CurrPtr = GetNextVariablePtr (Variable.CurrPtr, AuthFormat);
  }
 
  while (TRUE) {
    //
    // Switch to the next variable store if needed
    //
    while (!IsValidVariableHeader (Variable.CurrPtr, Variable.EndPtr)) {
      //
      // Find current storage index
      //
      for (StoreType = (VARIABLE_STORE_TYPE)0; StoreType < VariableStoreTypeMax; StoreType++) {
        if ((VariableStoreList[StoreType] != NULL) && (Variable.StartPtr == GetStartPointer (VariableStoreList[StoreType]))) {
          break;
        }
      }
 
      ASSERT (StoreType < VariableStoreTypeMax);
      //
      // Switch to next storage
      //
      for (StoreType++; StoreType < VariableStoreTypeMax; StoreType++) {
        if (VariableStoreList[StoreType] != NULL) {
          break;
        }
      }
 
      //
      // Capture the case that
      // 1. current storage is the last one, or
      // 2. no further storage
      //
      if (StoreType == VariableStoreTypeMax) {
        Status = EFI_NOT_FOUND;
        goto Done;
      }
 
      Variable.StartPtr = GetStartPointer (VariableStoreList[StoreType]);
      Variable.EndPtr   = GetEndPointer (VariableStoreList[StoreType]);
      Variable.CurrPtr  = Variable.StartPtr;
    }
 
    //
    // Variable is found
    //
    if ((Variable.CurrPtr->State == VAR_ADDED) || (Variable.CurrPtr->State == (VAR_IN_DELETED_TRANSITION & VAR_ADDED))) {
      if (!AtRuntime () || ((Variable.CurrPtr->Attributes & EFI_VARIABLE_RUNTIME_ACCESS) != 0)) {
        if (Variable.CurrPtr->State == (VAR_IN_DELETED_TRANSITION & VAR_ADDED)) {
          //
          // If it is a IN_DELETED_TRANSITION variable,
          // and there is also a same ADDED one at the same time,
          // don't return it.
          //
          VariablePtrTrack.StartPtr = Variable.StartPtr;
          VariablePtrTrack.EndPtr   = Variable.EndPtr;
          Status                    = FindVariableEx (
                                        GetVariableNamePtr (Variable.CurrPtr, AuthFormat),
                                        GetVendorGuidPtr (Variable.CurrPtr, AuthFormat),
                                        FALSE,
                                        &VariablePtrTrack,
                                        AuthFormat
                                        );
          if (!EFI_ERROR (Status) && (VariablePtrTrack.CurrPtr->State == VAR_ADDED)) {
            Variable.CurrPtr = GetNextVariablePtr (Variable.CurrPtr, AuthFormat);
            continue;
          }
        }
 
        //
        // Don't return NV variable when HOB overrides it
        //
        if ((VariableStoreList[VariableStoreTypeHob] != NULL) && (VariableStoreList[VariableStoreTypeNv] != NULL) &&
            (Variable.StartPtr == GetStartPointer (VariableStoreList[VariableStoreTypeNv]))
            )
        {
          VariableInHob.StartPtr = GetStartPointer (VariableStoreList[VariableStoreTypeHob]);
          VariableInHob.EndPtr   = GetEndPointer (VariableStoreList[VariableStoreTypeHob]);
          Status                 = FindVariableEx (
                                     GetVariableNamePtr (Variable.CurrPtr, AuthFormat),
                                     GetVendorGuidPtr (Variable.CurrPtr, AuthFormat),
                                     FALSE,
                                     &VariableInHob,
                                     AuthFormat
                                     );
          if (!EFI_ERROR (Status)) {
            Variable.CurrPtr = GetNextVariablePtr (Variable.CurrPtr, AuthFormat);
            continue;
          }
        }
 
        *VariablePtr = Variable.CurrPtr;
        Status       = EFI_SUCCESS;
        goto Done;
      }
    }
 
    Variable.CurrPtr = GetNextVariablePtr (Variable.CurrPtr, AuthFormat);
  }
 
Done:
  return Status;
}
 
VOID
UpdateVariableInfo (
  IN  CHAR16                  *VariableName,
  IN  EFI_GUID                *VendorGuid,
  IN  BOOLEAN                 Volatile,
  IN  BOOLEAN                 Read,
  IN  BOOLEAN                 Write,
  IN  BOOLEAN                 Delete,
  IN  BOOLEAN                 Cache,
  IN OUT VARIABLE_INFO_ENTRY  **VariableInfo
  )
{
  VARIABLE_INFO_ENTRY  *Entry;
 
  if (FeaturePcdGet (PcdVariableCollectStatistics)) {
    if ((VariableName == NULL) || (VendorGuid == NULL) || (VariableInfo == NULL)) {
      return;
    }
 
    if (AtRuntime ()) {
      // Don't collect statistics at runtime.
      return;
    }
 
    if (*VariableInfo == NULL) {
      //
      // On the first call allocate a entry and place a pointer to it in
      // the EFI System Table.
      //
      *VariableInfo = AllocateZeroPool (sizeof (VARIABLE_INFO_ENTRY));
      ASSERT (*VariableInfo != NULL);
 
      CopyGuid (&(*VariableInfo)->VendorGuid, VendorGuid);
      (*VariableInfo)->Name = AllocateZeroPool (StrSize (VariableName));
      ASSERT ((*VariableInfo)->Name != NULL);
      StrCpyS ((*VariableInfo)->Name, StrSize (VariableName)/sizeof (CHAR16), VariableName);
      (*VariableInfo)->Volatile = Volatile;
    }
 
    for (Entry = (*VariableInfo); Entry != NULL; Entry = Entry->Next) {
      if (CompareGuid (VendorGuid, &Entry->VendorGuid)) {
        if (StrCmp (VariableName, Entry->Name) == 0) {
          if (Read) {
            Entry->ReadCount++;
          }
 
          if (Write) {
            Entry->WriteCount++;
          }
 
          if (Delete) {
            Entry->DeleteCount++;
          }
 
          if (Cache) {
            Entry->CacheCount++;
          }
 
          return;
        }
      }
 
      if (Entry->Next == NULL) {
        //
        // If the entry is not in the table add it.
        // Next iteration of the loop will fill in the data.
        //
        Entry->Next = AllocateZeroPool (sizeof (VARIABLE_INFO_ENTRY));
        ASSERT (Entry->Next != NULL);
 
        CopyGuid (&Entry->Next->VendorGuid, VendorGuid);
        Entry->Next->Name = AllocateZeroPool (StrSize (VariableName));
        ASSERT (Entry->Next->Name != NULL);
        StrCpyS (Entry->Next->Name, StrSize (VariableName)/sizeof (CHAR16), VariableName);
        Entry->Next->Volatile = Volatile;
      }
    }
  }
}