FatPkg: Adds support for read-only mode

Implements gEfiFatPkgTokenSpaceGuid token space and adds token which
disables write operations. By default driver still supports read-write
mode

Signed-off-by: Savva Mitrofanov <savvamtr@gmail.com>
This commit is contained in:
Mikhail Krichanov 2023-04-20 11:47:10 +03:00
parent 30afd72eaf
commit ba02e8cc6c
10 changed files with 88 additions and 2 deletions

View File

@ -44,7 +44,7 @@ FatDelete (
//
// If the file is read-only, then don't delete it
//
if (IFile->ReadOnly) {
if (IFile->ReadOnly || FeaturePcdGet (PcdFatReadOnlyMode)) {
Status = EFI_WRITE_PROTECTED;
goto Done;
}

View File

@ -73,6 +73,10 @@ FatStoreDirEnt (
UINT8 EntryCount;
UINT8 LfnOrdinal;
if (FeaturePcdGet (PcdFatReadOnlyMode)) {
return EFI_WRITE_PROTECTED;
}
EntryPos = DirEnt->EntryPos;
EntryCount = DirEnt->EntryCount;
//
@ -709,6 +713,9 @@ FatExpandODir (
IN FAT_OFILE *OFile
)
{
if (FeaturePcdGet (PcdFatReadOnlyMode)) {
return EFI_WRITE_PROTECTED;
}
return FatExpandOFile (OFile, OFile->FileSize + OFile->Volume->ClusterSize);
}
@ -954,6 +961,10 @@ FatSetVolumeEntry (
FAT_DIRENT LabelDirEnt;
FAT_OFILE *Root;
if (FeaturePcdGet (PcdFatReadOnlyMode)) {
return EFI_WRITE_PROTECTED;
}
Root = Volume->Root;
Status = FatSeekVolumeId (Volume->Root, &LabelDirEnt);
if (EFI_ERROR (Status)) {
@ -1001,6 +1012,10 @@ FatCreateDotDirEnts (
EFI_STATUS Status;
FAT_DIRENT *DirEnt;
if (FeaturePcdGet (PcdFatReadOnlyMode)) {
return EFI_WRITE_PROTECTED;
}
Status = FatExpandODir (OFile);
if (EFI_ERROR (Status)) {
return Status;
@ -1048,6 +1063,10 @@ FatCreateDirEnt (
FAT_ODIR *ODir;
EFI_STATUS Status;
if (FeaturePcdGet (PcdFatReadOnlyMode)) {
return EFI_WRITE_PROTECTED;
}
ASSERT (OFile != NULL);
ODir = OFile->ODir;
ASSERT (ODir != NULL);
@ -1105,6 +1124,10 @@ FatRemoveDirEnt (
{
FAT_ODIR *ODir;
if (FeaturePcdGet (PcdFatReadOnlyMode)) {
return EFI_WRITE_PROTECTED;
}
ODir = OFile->ODir;
if (ODir->CurrentCursor == &DirEnt->Link) {
//

View File

@ -56,6 +56,7 @@
[Packages]
MdePkg/MdePkg.dec
FatPkg/FatPkg.dec
[LibraryClasses]
UefiRuntimeServicesTableLib
@ -82,6 +83,7 @@
gEfiUnicodeCollation2ProtocolGuid ## TO_START
[Pcd]
gEfiFatPkgTokenSpaceGuid.PcdFatReadOnlyMode ## CONSUMES
gEfiMdePkgTokenSpaceGuid.PcdUefiVariableDefaultLang ## SOMETIMES_CONSUMES
gEfiMdePkgTokenSpaceGuid.PcdUefiVariableDefaultPlatformLang ## SOMETIMES_CONSUMES
[UserExtensions.TianoCore."ExtraFiles"]

View File

@ -362,6 +362,10 @@ FatShrinkEof (
UINTN Cluster;
UINTN LastCluster;
if (FeaturePcdGet (PcdFatReadOnlyMode)) {
return EFI_WRITE_PROTECTED;
}
Volume = OFile->Volume;
ASSERT_VOLUME_LOCKED (Volume);
@ -440,6 +444,10 @@ FatGrowEof (
UINTN NewCluster;
UINTN ClusterCount;
if (FeaturePcdGet (PcdFatReadOnlyMode)) {
return EFI_WRITE_PROTECTED;
}
//
// For FAT file system, the max file is 4GB.
//

View File

@ -35,6 +35,10 @@ FatFlushEx (
EFI_STATUS Status;
FAT_TASK *Task;
if (FeaturePcdGet (PcdFatReadOnlyMode)) {
return EFI_WRITE_PROTECTED;
}
IFile = IFILE_FROM_FHAND (FHand);
OFile = IFile->OFile;
Volume = OFile->Volume;
@ -112,6 +116,9 @@ FatFlush (
IN EFI_FILE_PROTOCOL *FHand
)
{
if (FeaturePcdGet (PcdFatReadOnlyMode)) {
return EFI_WRITE_PROTECTED;
}
return FatFlushEx (FHand, NULL);
}

View File

@ -51,7 +51,7 @@ FatAllocateVolume (
Volume->DiskIo2 = DiskIo2;
Volume->BlockIo = BlockIo;
Volume->MediaId = BlockIo->Media->MediaId;
Volume->ReadOnly = BlockIo->Media->ReadOnly;
Volume->ReadOnly = BlockIo->Media->ReadOnly || FeaturePcdGet (PcdFatReadOnlyMode);
Volume->VolumeInterface.Revision = EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_REVISION;
Volume->VolumeInterface.OpenVolume = FatOpenVolume;
InitializeListHead (&Volume->CheckRef);

View File

@ -224,8 +224,12 @@ FatOpenEx (
//
switch (OpenMode) {
case EFI_FILE_MODE_READ:
break;
case EFI_FILE_MODE_READ | EFI_FILE_MODE_WRITE:
case EFI_FILE_MODE_READ | EFI_FILE_MODE_WRITE | EFI_FILE_MODE_CREATE:
if (FeaturePcdGet (PcdFatReadOnlyMode)) {
return EFI_WRITE_PROTECTED;
}
break;
default:

View File

@ -211,6 +211,10 @@ FatIFileAccess (
UINT64 EndPosition;
FAT_TASK *Task;
if (FeaturePcdGet (PcdFatReadOnlyMode) && IoMode == WriteData) {
return EFI_WRITE_PROTECTED;
}
IFile = IFILE_FROM_FHAND (FHand);
OFile = IFile->OFile;
Volume = OFile->Volume;
@ -414,6 +418,9 @@ FatWrite (
IN VOID *Buffer
)
{
if (FeaturePcdGet (PcdFatReadOnlyMode)) {
return EFI_WRITE_PROTECTED;
}
return FatIFileAccess (FHand, WriteData, BufferSize, Buffer, NULL);
}
@ -437,6 +444,9 @@ FatWriteEx (
IN OUT EFI_FILE_IO_TOKEN *Token
)
{
if (FeaturePcdGet (PcdFatReadOnlyMode)) {
return EFI_WRITE_PROTECTED;
}
return FatIFileAccess (FHand, WriteData, &Token->BufferSize, Token->Buffer, Token);
}
@ -471,6 +481,10 @@ FatAccessOFile (
EFI_STATUS Status;
UINTN BufferSize;
if (FeaturePcdGet (PcdFatReadOnlyMode) && IoMode == WriteData) {
return EFI_WRITE_PROTECTED;
}
BufferSize = *DataBufferSize;
Volume = OFile->Volume;
ASSERT_VOLUME_LOCKED (Volume);
@ -542,6 +556,10 @@ FatExpandOFile (
EFI_STATUS Status;
UINTN WritePos;
if (FeaturePcdGet (PcdFatReadOnlyMode)) {
return EFI_WRITE_PROTECTED;
}
WritePos = OFile->FileSize;
Status = FatGrowEof (OFile, ExpandedSize);
if (!EFI_ERROR (Status)) {
@ -575,6 +593,10 @@ FatWriteZeroPool (
UINTN BufferSize;
UINTN WriteSize;
if (FeaturePcdGet (PcdFatReadOnlyMode)) {
return EFI_WRITE_PROTECTED;
}
AppendedSize = OFile->FileSize - WritePos;
BufferSize = AppendedSize;
if (AppendedSize > FAT_MAX_ALLOCATE_SIZE) {
@ -624,6 +646,10 @@ FatTruncateOFile (
IN UINTN TruncatedSize
)
{
if (FeaturePcdGet (PcdFatReadOnlyMode)) {
return EFI_WRITE_PROTECTED;
}
OFile->FileSize = TruncatedSize;
return FatShrinkEof (OFile);
}

View File

@ -17,3 +17,16 @@
[UserExtensions.TianoCore."ExtraFiles"]
FatPkgExtra.uni
[Guids]
#
# GUID defined in package
#
gEfiFatPkgTokenSpaceGuid = { 0xbe1f59ff, 0x65f5, 0x4b28, {0xb2, 0x8d, 0x56, 0x85, 0x36, 0x4a, 0xb1, 0xd2 } }
[PcdsFeatureFlag.common]
## Indicates if driver is in read-only mode.<BR><BR>
# TRUE - Restricts write operations.<BR>
# FALSE - Write operations allowed. Default behavior<BR>
# @Prompt Disables write operations on fat filesystem.
gEfiFatPkgTokenSpaceGuid.PcdFatReadOnlyMode |FALSE|BOOLEAN|0x00000001

View File

@ -82,3 +82,6 @@
[Components]
FatPkg/FatPei/FatPei.inf
FatPkg/EnhancedFatDxe/Fat.inf
[PcdsFeatureFlag]
gEfiFatPkgTokenSpaceGuid.PcdFatReadOnlyMode|FALSE