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

Using the functions introduced previously, we can now implement the rename
operation in VirtioFsSimpleFileSetInfo().

Attribute updates come later.

Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3097
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20201216211125.19496-44-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>

1 files changed, 233 insertions, 1 deletions

diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsSetInfo.c b/OvmfPkg/VirtioFsDxe/SimpleFsSetInfo.c
index 895b5c029a..55169dde78 100644
--- a/OvmfPkg/VirtioFsDxe/SimpleFsSetInfo.c
+++ b/OvmfPkg/VirtioFsDxe/SimpleFsSetInfo.c
@@ -10,6 +10,7 @@
 #include <Guid/FileSystemVolumeLabelInfo.h> // gEfiFileSystemVolumeLabelInfo...

 #include <Library/BaseLib.h>                // StrCmp()

 #include <Library/BaseMemoryLib.h>          // CompareGuid()

+#include <Library/MemoryAllocationLib.h>    // FreePool()

 

 #include "VirtioFsDxe.h"

 

@@ -128,6 +129,237 @@ ValidateInfoStructure (
 }

 

 /**

+  Rename a VIRTIO_FS_FILE as requested in EFI_FILE_INFO.FileName.

+

+  @param[in,out] VirtioFsFile  The VIRTIO_FS_FILE to rename.

+

+  @param[in] NewFileName       The new file name requested by

+                               EFI_FILE_PROTOCOL.SetInfo().

+

+  @retval EFI_SUCCESS        The canonical format destination path that is

+                             determined from the input value of

+                             VirtioFsFile->CanonicalPathname and from

+                             NewFileName is identical to the input value of

+                             VirtioFsFile->CanonicalPathname. This means that

+                             EFI_FILE_INFO does not constitute a rename

+                             request. VirtioFsFile has not been changed.

+

+  @retval EFI_SUCCESS        VirtioFsFile has been renamed.

+                             VirtioFsFile->CanonicalPathname has assumed the

+                             destination pathname in canonical format.

+

+  @retval EFI_ACCESS_DENIED  VirtioFsFile refers to the root directory, and

+                             NewFileName expresses an actual rename/move

+                             request.

+

+  @retval EFI_ACCESS_DENIED  VirtioFsFile is the (possibly indirect) parent

+                             directory of at least one other VIRTIO_FS_FILE

+                             that is open for the same Virtio Filesystem

+                             (identified by VirtioFsFile->OwnerFs). Renaming

+                             VirtioFsFile would invalidate the canonical

+                             pathnames of those VIRTIO_FS_FILE instances;

+                             therefore the request has been rejected.

+

+  @retval EFI_ACCESS_DENIED  VirtioFsFile is not open for writing, but

+                             NewFileName expresses an actual rename/move

+                             request.

+

+  @retval EFI_NOT_FOUND      At least one dot-dot component in NewFileName

+                             attempted to escape the root directory.

+

+  @return                    Error codes propagated from underlying functions.

+**/

+STATIC

+EFI_STATUS

+Rename (

+  IN OUT VIRTIO_FS_FILE *VirtioFsFile,

+  IN     CHAR16         *NewFileName

+  )

+{

+

+  VIRTIO_FS  *VirtioFs;

+  EFI_STATUS Status;

+  CHAR8      *Destination;

+  BOOLEAN    RootEscape;

+  UINT64     OldParentDirNodeId;

+  CHAR8      *OldLastComponent;

+  UINT64     NewParentDirNodeId;

+  CHAR8      *NewLastComponent;

+

+  VirtioFs = VirtioFsFile->OwnerFs;

+

+  //

+  // The root directory cannot be renamed.

+  //

+  if (AsciiStrCmp (VirtioFsFile->CanonicalPathname, "/") == 0) {

+    if (StrCmp (NewFileName, L"") == 0) {

+      //

+      // Not a rename request anyway.

+      //

+      return EFI_SUCCESS;

+    }

+    return EFI_ACCESS_DENIED;

+  }

+

+  //

+  // Compose the canonical pathname for the destination.

+  //

+  Status = VirtioFsComposeRenameDestination (VirtioFsFile->CanonicalPathname,

+             NewFileName, &Destination, &RootEscape);

+  if (EFI_ERROR (Status)) {

+    return Status;

+  }

+  if (RootEscape) {

+    Status = EFI_NOT_FOUND;

+    goto FreeDestination;

+  }

+  //

+  // If the rename would leave VirtioFsFile->CanonicalPathname unchanged, then

+  // EFI_FILE_PROTOCOL.SetInfo() isn't asking for a rename actually.

+  //

+  if (AsciiStrCmp (VirtioFsFile->CanonicalPathname, Destination) == 0) {

+    Status = EFI_SUCCESS;

+    goto FreeDestination;

+  }

+  //

+  // Check if the rename would break the canonical pathnames of other

+  // VIRTIO_FS_FILE instances of the same VIRTIO_FS.

+  //

+  if (VirtioFsFile->IsDirectory) {

+    UINTN      PathLen;

+    LIST_ENTRY *OpenFilesEntry;

+

+    PathLen = AsciiStrLen (VirtioFsFile->CanonicalPathname);

+    BASE_LIST_FOR_EACH (OpenFilesEntry, &VirtioFs->OpenFiles) {

+      VIRTIO_FS_FILE *OtherFile;

+

+      OtherFile = VIRTIO_FS_FILE_FROM_OPEN_FILES_ENTRY (OpenFilesEntry);

+      if (OtherFile != VirtioFsFile &&

+          AsciiStrnCmp (VirtioFsFile->CanonicalPathname,

+            OtherFile->CanonicalPathname, PathLen) == 0 &&

+          (OtherFile->CanonicalPathname[PathLen] == '\0' ||

+           OtherFile->CanonicalPathname[PathLen] == '/')) {

+        //

+        // OtherFile refers to the same directory as VirtioFsFile, or is a

+        // (possibly indirect) child of the directory referred to by

+        // VirtioFsFile.

+        //

+        Status = EFI_ACCESS_DENIED;

+        goto FreeDestination;

+      }

+    }

+  }

+  //

+  // From this point on, the file needs to be open for writing.

+  //

+  if (!VirtioFsFile->IsOpenForWriting) {

+    Status = EFI_ACCESS_DENIED;

+    goto FreeDestination;

+  }

+  //

+  // Split both source and destination canonical pathnames into (most specific

+  // parent directory, last component) pairs.

+  //

+  Status = VirtioFsLookupMostSpecificParentDir (VirtioFs,

+             VirtioFsFile->CanonicalPathname, &OldParentDirNodeId,

+             &OldLastComponent);

+  if (EFI_ERROR (Status)) {

+    goto FreeDestination;

+  }

+  Status = VirtioFsLookupMostSpecificParentDir (VirtioFs, Destination,

+             &NewParentDirNodeId, &NewLastComponent);

+  if (EFI_ERROR (Status)) {

+    goto ForgetOldParentDirNodeId;

+  }

+  //

+  // Perform the rename. If the destination path exists, the rename will fail.

+  //

+  Status = VirtioFsFuseRename (VirtioFs, OldParentDirNodeId, OldLastComponent,

+             NewParentDirNodeId, NewLastComponent);

+  if (EFI_ERROR (Status)) {

+    goto ForgetNewParentDirNodeId;

+  }

+

+  //

+  // Swap in the new canonical pathname.

+  //

+  FreePool (VirtioFsFile->CanonicalPathname);

+  VirtioFsFile->CanonicalPathname = Destination;

+  Destination = NULL;

+  Status = EFI_SUCCESS;

+

+  //

+  // Fall through.

+  //

+ForgetNewParentDirNodeId:

+  if (NewParentDirNodeId != VIRTIO_FS_FUSE_ROOT_DIR_NODE_ID) {

+    VirtioFsFuseForget (VirtioFs, NewParentDirNodeId);

+  }

+

+ForgetOldParentDirNodeId:

+  if (OldParentDirNodeId != VIRTIO_FS_FUSE_ROOT_DIR_NODE_ID) {

+    VirtioFsFuseForget (VirtioFs, OldParentDirNodeId);

+  }

+

+FreeDestination:

+  if (Destination != NULL) {

+    FreePool (Destination);

+  }

+  return Status;

+}

+

+/**

+  Process an EFI_FILE_INFO setting request.

+**/

+STATIC

+EFI_STATUS

+SetFileInfo (

+  IN EFI_FILE_PROTOCOL *This,

+  IN UINTN             BufferSize,

+  IN VOID              *Buffer

+  )

+{

+  VIRTIO_FS_FILE *VirtioFsFile;

+  EFI_STATUS     Status;

+  EFI_FILE_INFO  *FileInfo;

+

+  VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);

+

+  //

+  // Validate if Buffer passes as EFI_FILE_INFO.

+  //

+  Status = ValidateInfoStructure (

+             BufferSize,                    // SizeByProtocolCaller

+             OFFSET_OF (EFI_FILE_INFO,

+               FileName) + sizeof (CHAR16), // MinimumStructSize

+             TRUE,                          // IsSizeByInfoPresent

+             Buffer

+             );

+  if (EFI_ERROR (Status)) {

+    return Status;

+  }

+  FileInfo = Buffer;

+

+  //

+  // Perform the rename/move request, if any.

+  //

+  Status = Rename (VirtioFsFile, FileInfo->FileName);

+  if (EFI_ERROR (Status)) {

+    return Status;

+  }

+  //

+  // Update any attributes requested.

+  //

+  Status = EFI_UNSUPPORTED;

+  //

+  // The UEFI spec does not speak about partial failure in

+  // EFI_FILE_PROTOCOL.SetInfo(); we won't try to roll back the rename (if

+  // there was one) in case the attribute updates fail.

+  //

+  return Status;

+}

+

+/**

   Process an EFI_FILE_SYSTEM_INFO setting request.

 **/

 STATIC

@@ -230,7 +462,7 @@ VirtioFsSimpleFileSetInfo (
   )

 {

   if (CompareGuid (InformationType, &gEfiFileInfoGuid)) {

-    return EFI_UNSUPPORTED;

+    return SetFileInfo (This, BufferSize, Buffer);

   }

 

   if (CompareGuid (InformationType, &gEfiFileSystemInfoGuid)) {