OvmfPkg/VirtioFsDxe: handle file rename/move in EFI_FILE_PROTOCOL.SetInfo

[mirror_edk2.git] / OvmfPkg / VirtioFsDxe / SimpleFsSetInfo.c

/** @file\r
  EFI_FILE_PROTOCOL.SetInfo() member function for the Virtio Filesystem driver.\r
\r
  Copyright (C) 2020, Red Hat, Inc.\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
**/\r
\r
#include <Guid/FileSystemInfo.h>            // gEfiFileSystemInfoGuid\r
#include <Guid/FileSystemVolumeLabelInfo.h> // gEfiFileSystemVolumeLabelInfo...\r
#include <Library/BaseLib.h>                // StrCmp()\r
#include <Library/BaseMemoryLib.h>          // CompareGuid()\r
#include <Library/MemoryAllocationLib.h>    // FreePool()\r
\r
#include "VirtioFsDxe.h"\r
\r
/**\r
  Validate a buffer that the EFI_FILE_PROTOCOL.SetInfo() caller passes in for a\r
  particular InformationType GUID.\r
\r
  The structure to be validated is supposed to end with a variable-length,\r
  NUL-terminated CHAR16 Name string.\r
\r
  @param[in] SizeByProtocolCaller  The BufferSize parameter as provided by the\r
                                   EFI_FILE_PROTOCOL.SetInfo() caller.\r
\r
  @param[in] MinimumStructSize     The minimum structure size that is required\r
                                   for the given InformationType GUID,\r
                                   including a single CHAR16 element from the\r
                                   trailing Name field.\r
\r
  @param[in] IsSizeByInfoPresent   TRUE if and only if the expected structure\r
                                   starts with a UINT64 Size field that reports\r
                                   the actual structure size.\r
\r
  @param[in] Buffer                The Buffer parameter as provided by the\r
                                   EFI_FILE_PROTOCOL.SetInfo() caller.\r
\r
  @retval EFI_SUCCESS            Validation successful, Buffer is well-formed.\r
\r
  @retval EFI_BAD_BUFFER_SIZE    The EFI_FILE_PROTOCOL.SetInfo()\r
                                 caller provided a BufferSize that is smaller\r
                                 than the minimum structure size required for\r
                                 the given InformationType GUID.\r
\r
  @retval EFI_INVALID_PARAMETER  IsSizeByInfoPresent is TRUE, and the leading\r
                                 UINT64 Size field does not match the\r
                                 EFI_FILE_PROTOCOL.SetInfo() caller-provided\r
                                 BufferSize.\r
\r
  @retval EFI_INVALID_PARAMETER  The trailing Name field does not consist of a\r
                                 whole multiple of CHAR16 elements.\r
\r
  @retval EFI_INVALID_PARAMETER  The trailing Name field is not NUL-terminated.\r
**/\r
STATIC\r
EFI_STATUS\r
ValidateInfoStructure (\r
  IN UINTN   SizeByProtocolCaller,\r
  IN UINTN   MinimumStructSize,\r
  IN BOOLEAN IsSizeByInfoPresent,\r
  IN VOID    *Buffer\r
  )\r
{\r
  UINTN  NameFieldByteOffset;\r
  UINTN  NameFieldBytes;\r
  UINTN  NameFieldChar16s;\r
  CHAR16 *NameField;\r
\r
  //\r
  // Make sure the internal function asking for validation passes in sane\r
  // values.\r
  //\r
  ASSERT (MinimumStructSize >= sizeof (CHAR16));\r
  NameFieldByteOffset = MinimumStructSize - sizeof (CHAR16);\r
\r
  if (IsSizeByInfoPresent) {\r
    ASSERT (MinimumStructSize >= sizeof (UINT64) + sizeof (CHAR16));\r
    ASSERT (NameFieldByteOffset >= sizeof (UINT64));\r
  }\r
\r
  //\r
  // Check whether the protocol caller provided enough bytes for the minimum\r
  // size of this info structure.\r
  //\r
  if (SizeByProtocolCaller < MinimumStructSize) {\r
    return EFI_BAD_BUFFER_SIZE;\r
  }\r
\r
  //\r
  // If the info structure starts with a UINT64 Size field, check if that\r
  // agrees with the protocol caller-provided size.\r
  //\r
  if (IsSizeByInfoPresent) {\r
    UINT64 *SizeByInfo;\r
\r
    SizeByInfo = Buffer;\r
    if (*SizeByInfo != SizeByProtocolCaller) {\r
      return EFI_INVALID_PARAMETER;\r
    }\r
  }\r
\r
  //\r
  // The CHAR16 Name field at the end of the structure must have an even number\r
  // of bytes.\r
  //\r
  // The subtraction below cannot underflow, and yields at least\r
  // sizeof(CHAR16).\r
  //\r
  ASSERT (SizeByProtocolCaller >= NameFieldByteOffset);\r
  NameFieldBytes = SizeByProtocolCaller - NameFieldByteOffset;\r
  ASSERT (NameFieldBytes >= sizeof (CHAR16));\r
  if (NameFieldBytes % sizeof (CHAR16) != 0) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  //\r
  // The CHAR16 Name field at the end of the structure must be NUL-terminated.\r
  //\r
  NameFieldChar16s = NameFieldBytes / sizeof (CHAR16);\r
  ASSERT (NameFieldChar16s >= 1);\r
\r
  NameField = (CHAR16 *)((UINT8 *)Buffer + NameFieldByteOffset);\r
  if (NameField[NameFieldChar16s - 1] != L'\0') {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Rename a VIRTIO_FS_FILE as requested in EFI_FILE_INFO.FileName.\r
\r
  @param[in,out] VirtioFsFile  The VIRTIO_FS_FILE to rename.\r
\r
  @param[in] NewFileName       The new file name requested by\r
                               EFI_FILE_PROTOCOL.SetInfo().\r
\r
  @retval EFI_SUCCESS        The canonical format destination path that is\r
                             determined from the input value of\r
                             VirtioFsFile->CanonicalPathname and from\r
                             NewFileName is identical to the input value of\r
                             VirtioFsFile->CanonicalPathname. This means that\r
                             EFI_FILE_INFO does not constitute a rename\r
                             request. VirtioFsFile has not been changed.\r
\r
  @retval EFI_SUCCESS        VirtioFsFile has been renamed.\r
                             VirtioFsFile->CanonicalPathname has assumed the\r
                             destination pathname in canonical format.\r
\r
  @retval EFI_ACCESS_DENIED  VirtioFsFile refers to the root directory, and\r
                             NewFileName expresses an actual rename/move\r
                             request.\r
\r
  @retval EFI_ACCESS_DENIED  VirtioFsFile is the (possibly indirect) parent\r
                             directory of at least one other VIRTIO_FS_FILE\r
                             that is open for the same Virtio Filesystem\r
                             (identified by VirtioFsFile->OwnerFs). Renaming\r
                             VirtioFsFile would invalidate the canonical\r
                             pathnames of those VIRTIO_FS_FILE instances;\r
                             therefore the request has been rejected.\r
\r
  @retval EFI_ACCESS_DENIED  VirtioFsFile is not open for writing, but\r
                             NewFileName expresses an actual rename/move\r
                             request.\r
\r
  @retval EFI_NOT_FOUND      At least one dot-dot component in NewFileName\r
                             attempted to escape the root directory.\r
\r
  @return                    Error codes propagated from underlying functions.\r
**/\r
STATIC\r
EFI_STATUS\r
Rename (\r
  IN OUT VIRTIO_FS_FILE *VirtioFsFile,\r
  IN     CHAR16         *NewFileName\r
  )\r
{\r
\r
  VIRTIO_FS  *VirtioFs;\r
  EFI_STATUS Status;\r
  CHAR8      *Destination;\r
  BOOLEAN    RootEscape;\r
  UINT64     OldParentDirNodeId;\r
  CHAR8      *OldLastComponent;\r
  UINT64     NewParentDirNodeId;\r
  CHAR8      *NewLastComponent;\r
\r
  VirtioFs = VirtioFsFile->OwnerFs;\r
\r
  //\r
  // The root directory cannot be renamed.\r
  //\r
  if (AsciiStrCmp (VirtioFsFile->CanonicalPathname, "/") == 0) {\r
    if (StrCmp (NewFileName, L"") == 0) {\r
      //\r
      // Not a rename request anyway.\r
      //\r
      return EFI_SUCCESS;\r
    }\r
    return EFI_ACCESS_DENIED;\r
  }\r
\r
  //\r
  // Compose the canonical pathname for the destination.\r
  //\r
  Status = VirtioFsComposeRenameDestination (VirtioFsFile->CanonicalPathname,\r
             NewFileName, &Destination, &RootEscape);\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
  if (RootEscape) {\r
    Status = EFI_NOT_FOUND;\r
    goto FreeDestination;\r
  }\r
  //\r
  // If the rename would leave VirtioFsFile->CanonicalPathname unchanged, then\r
  // EFI_FILE_PROTOCOL.SetInfo() isn't asking for a rename actually.\r
  //\r
  if (AsciiStrCmp (VirtioFsFile->CanonicalPathname, Destination) == 0) {\r
    Status = EFI_SUCCESS;\r
    goto FreeDestination;\r
  }\r
  //\r
  // Check if the rename would break the canonical pathnames of other\r
  // VIRTIO_FS_FILE instances of the same VIRTIO_FS.\r
  //\r
  if (VirtioFsFile->IsDirectory) {\r
    UINTN      PathLen;\r
    LIST_ENTRY *OpenFilesEntry;\r
\r
    PathLen = AsciiStrLen (VirtioFsFile->CanonicalPathname);\r
    BASE_LIST_FOR_EACH (OpenFilesEntry, &VirtioFs->OpenFiles) {\r
      VIRTIO_FS_FILE *OtherFile;\r
\r
      OtherFile = VIRTIO_FS_FILE_FROM_OPEN_FILES_ENTRY (OpenFilesEntry);\r
      if (OtherFile != VirtioFsFile &&\r
          AsciiStrnCmp (VirtioFsFile->CanonicalPathname,\r
            OtherFile->CanonicalPathname, PathLen) == 0 &&\r
          (OtherFile->CanonicalPathname[PathLen] == '\0' ||\r
           OtherFile->CanonicalPathname[PathLen] == '/')) {\r
        //\r
        // OtherFile refers to the same directory as VirtioFsFile, or is a\r
        // (possibly indirect) child of the directory referred to by\r
        // VirtioFsFile.\r
        //\r
        Status = EFI_ACCESS_DENIED;\r
        goto FreeDestination;\r
      }\r
    }\r
  }\r
  //\r
  // From this point on, the file needs to be open for writing.\r
  //\r
  if (!VirtioFsFile->IsOpenForWriting) {\r
    Status = EFI_ACCESS_DENIED;\r
    goto FreeDestination;\r
  }\r
  //\r
  // Split both source and destination canonical pathnames into (most specific\r
  // parent directory, last component) pairs.\r
  //\r
  Status = VirtioFsLookupMostSpecificParentDir (VirtioFs,\r
             VirtioFsFile->CanonicalPathname, &OldParentDirNodeId,\r
             &OldLastComponent);\r
  if (EFI_ERROR (Status)) {\r
    goto FreeDestination;\r
  }\r
  Status = VirtioFsLookupMostSpecificParentDir (VirtioFs, Destination,\r
             &NewParentDirNodeId, &NewLastComponent);\r
  if (EFI_ERROR (Status)) {\r
    goto ForgetOldParentDirNodeId;\r
  }\r
  //\r
  // Perform the rename. If the destination path exists, the rename will fail.\r
  //\r
  Status = VirtioFsFuseRename (VirtioFs, OldParentDirNodeId, OldLastComponent,\r
             NewParentDirNodeId, NewLastComponent);\r
  if (EFI_ERROR (Status)) {\r
    goto ForgetNewParentDirNodeId;\r
  }\r
\r
  //\r
  // Swap in the new canonical pathname.\r
  //\r
  FreePool (VirtioFsFile->CanonicalPathname);\r
  VirtioFsFile->CanonicalPathname = Destination;\r
  Destination = NULL;\r
  Status = EFI_SUCCESS;\r
\r
  //\r
  // Fall through.\r
  //\r
ForgetNewParentDirNodeId:\r
  if (NewParentDirNodeId != VIRTIO_FS_FUSE_ROOT_DIR_NODE_ID) {\r
    VirtioFsFuseForget (VirtioFs, NewParentDirNodeId);\r
  }\r
\r
ForgetOldParentDirNodeId:\r
  if (OldParentDirNodeId != VIRTIO_FS_FUSE_ROOT_DIR_NODE_ID) {\r
    VirtioFsFuseForget (VirtioFs, OldParentDirNodeId);\r
  }\r
\r
FreeDestination:\r
  if (Destination != NULL) {\r
    FreePool (Destination);\r
  }\r
  return Status;\r
}\r
\r
/**\r
  Process an EFI_FILE_INFO setting request.\r
**/\r
STATIC\r
EFI_STATUS\r
SetFileInfo (\r
  IN EFI_FILE_PROTOCOL *This,\r
  IN UINTN             BufferSize,\r
  IN VOID              *Buffer\r
  )\r
{\r
  VIRTIO_FS_FILE *VirtioFsFile;\r
  EFI_STATUS     Status;\r
  EFI_FILE_INFO  *FileInfo;\r
\r
  VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);\r
\r
  //\r
  // Validate if Buffer passes as EFI_FILE_INFO.\r
  //\r
  Status = ValidateInfoStructure (\r
             BufferSize,                    // SizeByProtocolCaller\r
             OFFSET_OF (EFI_FILE_INFO,\r
               FileName) + sizeof (CHAR16), // MinimumStructSize\r
             TRUE,                          // IsSizeByInfoPresent\r
             Buffer\r
             );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
  FileInfo = Buffer;\r
\r
  //\r
  // Perform the rename/move request, if any.\r
  //\r
  Status = Rename (VirtioFsFile, FileInfo->FileName);\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
  //\r
  // Update any attributes requested.\r
  //\r
  Status = EFI_UNSUPPORTED;\r
  //\r
  // The UEFI spec does not speak about partial failure in\r
  // EFI_FILE_PROTOCOL.SetInfo(); we won't try to roll back the rename (if\r
  // there was one) in case the attribute updates fail.\r
  //\r
  return Status;\r
}\r
\r
/**\r
  Process an EFI_FILE_SYSTEM_INFO setting request.\r
**/\r
STATIC\r
EFI_STATUS\r
SetFileSystemInfo (\r
  IN EFI_FILE_PROTOCOL *This,\r
  IN UINTN             BufferSize,\r
  IN VOID              *Buffer\r
  )\r
{\r
  VIRTIO_FS_FILE       *VirtioFsFile;\r
  VIRTIO_FS            *VirtioFs;\r
  EFI_STATUS           Status;\r
  EFI_FILE_SYSTEM_INFO *FileSystemInfo;\r
\r
  VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);\r
  VirtioFs     = VirtioFsFile->OwnerFs;\r
\r
  //\r
  // Validate if Buffer passes as EFI_FILE_SYSTEM_INFO.\r
  //\r
  Status = ValidateInfoStructure (\r
             BufferSize,                       // SizeByProtocolCaller\r
             OFFSET_OF (EFI_FILE_SYSTEM_INFO,\r
               VolumeLabel) + sizeof (CHAR16), // MinimumStructSize\r
             TRUE,                             // IsSizeByInfoPresent\r
             Buffer\r
             );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
  FileSystemInfo = Buffer;\r
\r
  //\r
  // EFI_FILE_SYSTEM_INFO fields other than VolumeLabel cannot be changed, per\r
  // spec.\r
  //\r
  // If the label is being changed to its current value, report success;\r
  // otherwise, reject the request, as the Virtio Filesystem device does not\r
  // support changing the label.\r
  //\r
  if (StrCmp (FileSystemInfo->VolumeLabel, VirtioFs->Label) == 0) {\r
    return EFI_SUCCESS;\r
  }\r
  return EFI_WRITE_PROTECTED;\r
}\r
\r
/**\r
  Process an EFI_FILE_SYSTEM_VOLUME_LABEL setting request.\r
**/\r
STATIC\r
EFI_STATUS\r
SetFileSystemVolumeLabelInfo (\r
  IN EFI_FILE_PROTOCOL *This,\r
  IN UINTN             BufferSize,\r
  IN VOID              *Buffer\r
  )\r
{\r
  VIRTIO_FS_FILE               *VirtioFsFile;\r
  VIRTIO_FS                    *VirtioFs;\r
  EFI_STATUS                   Status;\r
  EFI_FILE_SYSTEM_VOLUME_LABEL *FileSystemVolumeLabel;\r
\r
  VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);\r
  VirtioFs     = VirtioFsFile->OwnerFs;\r
\r
  //\r
  // Validate if Buffer passes as EFI_FILE_SYSTEM_VOLUME_LABEL.\r
  //\r
  Status = ValidateInfoStructure (\r
             BufferSize,                              // SizeByProtocolCaller\r
             OFFSET_OF (EFI_FILE_SYSTEM_VOLUME_LABEL,\r
               VolumeLabel) + sizeof (CHAR16),        // MinimumStructSize\r
             FALSE,                                   // IsSizeByInfoPresent\r
             Buffer\r
             );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
  FileSystemVolumeLabel = Buffer;\r
\r
  //\r
  // If the label is being changed to its current value, report success;\r
  // otherwise, reject the request, as the Virtio Filesystem device does not\r
  // support changing the label.\r
  //\r
  if (StrCmp (FileSystemVolumeLabel->VolumeLabel, VirtioFs->Label) == 0) {\r
    return EFI_SUCCESS;\r
  }\r
  return EFI_WRITE_PROTECTED;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
VirtioFsSimpleFileSetInfo (\r
  IN EFI_FILE_PROTOCOL *This,\r
  IN EFI_GUID          *InformationType,\r
  IN UINTN             BufferSize,\r
  IN VOID              *Buffer\r
  )\r
{\r
  if (CompareGuid (InformationType, &gEfiFileInfoGuid)) {\r
    return SetFileInfo (This, BufferSize, Buffer);\r
  }\r
\r
  if (CompareGuid (InformationType, &gEfiFileSystemInfoGuid)) {\r
    return SetFileSystemInfo (This, BufferSize, Buffer);\r
  }\r
\r
  if (CompareGuid (InformationType, &gEfiFileSystemVolumeLabelInfoIdGuid)) {\r
    return SetFileSystemVolumeLabelInfo (This, BufferSize, Buffer);\r
  }\r
\r
  return EFI_UNSUPPORTED;\r
}\r