[edk2-devel] [edk2 PATCH 34/48] OvmfPkg/VirtioFsDxe: convert FUSE dirent filename to EFI_FILE_INFO
Laszlo Ersek
lersek at redhat.com
Wed Dec 16 21:11:11 UTC 2020
Introduce the VirtioFsFuseDirentPlusToEfiFileInfo() function, for
converting the VIRTIO_FS_FUSE_DIRENTPLUS_RESPONSE filename byte array to
EFI_FILE_INFO.
This new function updates those EFI_FILE_INFO fields (Size, FileName) that
the earlier helper function VirtioFsFuseAttrToEfiFileInfo() does not set.
Both functions together will be able to fill in EFI_FILE_INFO completely,
from FUSE_READDIRPLUS.
Cc: Ard Biesheuvel <ard.biesheuvel at arm.com>
Cc: Jordan Justen <jordan.l.justen at intel.com>
Cc: Philippe Mathieu-Daudé <philmd at redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3097
Signed-off-by: Laszlo Ersek <lersek at redhat.com>
---
OvmfPkg/VirtioFsDxe/VirtioFsDxe.h | 6 ++
OvmfPkg/VirtioFsDxe/Helpers.c | 79 ++++++++++++++++++++
2 files changed, 85 insertions(+)
diff --git a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
index f5501af7d0a4..2b419048c232 100644
--- a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
+++ b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
@@ -243,16 +243,22 @@ VirtioFsGetBasename (
);
EFI_STATUS
VirtioFsFuseAttrToEfiFileInfo (
IN VIRTIO_FS_FUSE_ATTRIBUTES_RESPONSE *FuseAttr,
OUT EFI_FILE_INFO *FileInfo
);
+EFI_STATUS
+VirtioFsFuseDirentPlusToEfiFileInfo (
+ IN VIRTIO_FS_FUSE_DIRENTPLUS_RESPONSE *FuseDirent,
+ IN OUT EFI_FILE_INFO *FileInfo
+ );
+
//
// Wrapper functions for FUSE commands (primitives).
//
EFI_STATUS
VirtioFsFuseLookup (
IN OUT VIRTIO_FS *VirtioFs,
IN UINT64 DirNodeId,
diff --git a/OvmfPkg/VirtioFsDxe/Helpers.c b/OvmfPkg/VirtioFsDxe/Helpers.c
index 77f718e91233..cdaa8557a17b 100644
--- a/OvmfPkg/VirtioFsDxe/Helpers.c
+++ b/OvmfPkg/VirtioFsDxe/Helpers.c
@@ -1895,8 +1895,87 @@ VirtioFsFuseAttrToEfiFileInfo (
// A hard link count greater than 1 is not supported for regular files.
//
if ((FileInfo->Attribute & EFI_FILE_DIRECTORY) == 0 && FuseAttr->Nlink > 1) {
return EFI_UNSUPPORTED;
}
return EFI_SUCCESS;
}
+
+/**
+ Convert a VIRTIO_FS_FUSE_DIRENTPLUS_RESPONSE filename to an EFI_FILE_INFO
+ filename.
+
+ @param[in] FuseDirent The VIRTIO_FS_FUSE_DIRENTPLUS_RESPONSE object to
+ convert the filename byte array from. The caller is
+ responsible for ensuring that FuseDirent->Namelen
+ describe valid storage.
+
+ @param[in,out] FileInfo The EFI_FILE_INFO structure to modify. On input, the
+ caller is responsible for setting FileInfo->Size
+ according to the allocated size. On successful
+ return, FileInfo->Size is reduced to reflect the
+ filename converted into FileInfo->FileName.
+ FileInfo->FileName is set from the filename byte
+ array that directly follows the FuseDirent header
+ object. Fields other than FileInfo->Size and
+ FileInfo->FileName are not modified.
+
+ @retval EFI_SUCCESS Conversion successful.
+
+ @retval EFI_INVALID_PARAMETER VIRTIO_FS_FUSE_DIRENTPLUS_RESPONSE_SIZE()
+ returns zero for FuseDirent->Namelen.
+
+ @retval EFI_BUFFER_TOO_SMALL On input, FileInfo->Size does not provide
+ enough room for converting the filename byte
+ array from FuseDirent.
+
+ @retval EFI_UNSUPPORTED The FuseDirent filename byte array contains a
+ byte that falls outside of the printable ASCII
+ range, or is a forward slash or a backslash.
+**/
+EFI_STATUS
+VirtioFsFuseDirentPlusToEfiFileInfo (
+ IN VIRTIO_FS_FUSE_DIRENTPLUS_RESPONSE *FuseDirent,
+ IN OUT EFI_FILE_INFO *FileInfo
+ )
+{
+ UINTN DirentSize;
+ UINTN FileInfoSize;
+ UINT8 *DirentName;
+ UINT32 Idx;
+
+ DirentSize = VIRTIO_FS_FUSE_DIRENTPLUS_RESPONSE_SIZE (FuseDirent->Namelen);
+ if (DirentSize == 0) {
+ return EFI_INVALID_PARAMETER;
+ }
+ //
+ // We're now safe from overflow in the calculation below.
+ //
+ FileInfoSize = (OFFSET_OF (EFI_FILE_INFO, FileName) +
+ ((UINTN)FuseDirent->Namelen + 1) * sizeof (CHAR16));
+ if (FileInfoSize > FileInfo->Size) {
+ return EFI_BUFFER_TOO_SMALL;
+ }
+
+ //
+ // Convert the name.
+ //
+ DirentName = (UINT8 *)(FuseDirent + 1);
+ for (Idx = 0; Idx < FuseDirent->Namelen; Idx++) {
+ UINT8 NameByte;
+
+ NameByte = DirentName[Idx];
+ if (NameByte < 0x20 || NameByte > 0x7E ||
+ NameByte == '/' || NameByte == '\\') {
+ return EFI_UNSUPPORTED;
+ }
+ FileInfo->FileName[Idx] = (CHAR16)NameByte;
+ }
+ FileInfo->FileName[Idx++] = L'\0';
+ //
+ // Set the (possibly reduced) size.
+ //
+ FileInfo->Size = FileInfoSize;
+
+ return EFI_SUCCESS;
+}
--
2.19.1.3.g30247aa5d201
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