diff options
| -rw-r--r-- | OvmfPkg/VirtioFsDxe/SimpleFsOpen.c | 480 |
1 files changed, 479 insertions, 1 deletions
diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsOpen.c b/OvmfPkg/VirtioFsDxe/SimpleFsOpen.c index f0e2491840..2649c796ac 100644 --- a/OvmfPkg/VirtioFsDxe/SimpleFsOpen.c +++ b/OvmfPkg/VirtioFsDxe/SimpleFsOpen.c @@ -6,8 +6,284 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
**/
+#include <Library/BaseLib.h> // AsciiStrCmp()
+#include <Library/MemoryAllocationLib.h> // AllocatePool()
+
#include "VirtioFsDxe.h"
+/**
+ Open the root directory, possibly for writing.
+
+ @param[in,out] VirtioFs The Virtio Filesystem device whose root directory
+ should be opened.
+
+ @param[out] NewHandle The new EFI_FILE_PROTOCOL instance through which
+ the root directory can be accessed.
+
+ @param[in] OpenForWriting TRUE if the root directory should be opened for
+ read-write access. FALSE if the root directory
+ should be opened for read-only access. Opening the
+ root directory for read-write access is useful for
+ calling EFI_FILE_PROTOCOL.Flush() or
+ EFI_FILE_PROTOCOL.SetInfo() later, for syncing or
+ touching the root directory, respectively.
+
+ @retval EFI_SUCCESS The root directory has been opened successfully.
+
+ @retval EFI_ACCESS_DENIED OpenForWriting is TRUE, but the root directory is
+ marked as read-only.
+
+ @return Error codes propagated from underlying functions.
+**/
+STATIC
+EFI_STATUS
+OpenRootDirectory (
+ IN OUT VIRTIO_FS *VirtioFs,
+ OUT EFI_FILE_PROTOCOL **NewHandle,
+ IN BOOLEAN OpenForWriting
+ )
+{
+ EFI_STATUS Status;
+ VIRTIO_FS_FILE *NewVirtioFsFile;
+
+ //
+ // VirtioFsOpenVolume() opens the root directory for read-only access. If the
+ // current request is to open the root directory for read-write access, so
+ // that EFI_FILE_PROTOCOL.Flush() or EFI_FILE_PROTOCOL.SetInfo()+timestamps
+ // can be used on the root directory later, then we have to check for write
+ // permission first.
+ //
+ if (OpenForWriting) {
+ VIRTIO_FS_FUSE_ATTRIBUTES_RESPONSE FuseAttr;
+ EFI_FILE_INFO FileInfo;
+
+ Status = VirtioFsFuseGetAttr (VirtioFs, VIRTIO_FS_FUSE_ROOT_DIR_NODE_ID,
+ &FuseAttr);
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+ Status = VirtioFsFuseAttrToEfiFileInfo (&FuseAttr, &FileInfo);
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+ if ((FileInfo.Attribute & EFI_FILE_READ_ONLY) != 0) {
+ return EFI_ACCESS_DENIED;
+ }
+ }
+
+ Status = VirtioFsOpenVolume (&VirtioFs->SimpleFs, NewHandle);
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ NewVirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (*NewHandle);
+ NewVirtioFsFile->IsOpenForWriting = OpenForWriting;
+ return EFI_SUCCESS;
+}
+
+/**
+ Open an existent regular file or non-root directory.
+
+ @param[in,out] VirtioFs The Virtio Filesystem device on which the
+ regular file or directory should be opened.
+
+ @param[in] DirNodeId The inode number of the immediate parent
+ directory of the regular file or directory to
+ open.
+
+ @param[in] Name The single-component filename of the regular
+ file or directory to open, under the immediate
+ parent directory identified by DirNodeId.
+
+ @param[in] OpenForWriting TRUE if the regular file or directory should be
+ opened for read-write access. FALSE if the
+ regular file or directory should be opened for
+ read-only access. Opening a directory for
+ read-write access is useful for deleting,
+ renaming, syncing or touching the directory
+ later.
+
+ @param[out] NodeId The inode number of the regular file or
+ directory, returned by the Virtio Filesystem
+ device.
+
+ @param[out] FuseHandle The open handle to the regular file or
+ directory, returned by the Virtio Filesystem
+ device.
+
+ @param[out] NodeIsDirectory Set to TRUE on output if Name was found to refer
+ to a directory. Set to FALSE if Name was found
+ to refer to a regular file.
+
+ @retval EFI_SUCCESS The regular file or directory has been looked up
+ and opened successfully.
+
+ @retval EFI_ACCESS_DENIED OpenForWriting is TRUE, but the regular file or
+ directory is marked read-only.
+
+ @retval EFI_NOT_FOUND A directory entry called Name was not found in the
+ directory identified by DirNodeId. (EFI_NOT_FOUND
+ is not returned for any other condition.)
+
+ @return Errors propagated from underlying functions. If
+ the error code to propagate were EFI_NOT_FOUND, it
+ is remapped to EFI_DEVICE_ERROR.
+**/
+STATIC
+EFI_STATUS
+OpenExistentFileOrDirectory (
+ IN OUT VIRTIO_FS *VirtioFs,
+ IN UINT64 DirNodeId,
+ IN CHAR8 *Name,
+ IN BOOLEAN OpenForWriting,
+ OUT UINT64 *NodeId,
+ OUT UINT64 *FuseHandle,
+ OUT BOOLEAN *NodeIsDirectory
+ )
+{
+ EFI_STATUS Status;
+ UINT64 ResolvedNodeId;
+ VIRTIO_FS_FUSE_ATTRIBUTES_RESPONSE FuseAttr;
+ EFI_FILE_INFO FileInfo;
+ BOOLEAN IsDirectory;
+ UINT64 NewFuseHandle;
+
+ Status = VirtioFsFuseLookup (VirtioFs, DirNodeId, Name, &ResolvedNodeId,
+ &FuseAttr);
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+ Status = VirtioFsFuseAttrToEfiFileInfo (&FuseAttr, &FileInfo);
+ if (EFI_ERROR (Status)) {
+ goto ForgetResolvedNodeId;
+ }
+
+ if (OpenForWriting && (FileInfo.Attribute & EFI_FILE_READ_ONLY) != 0) {
+ Status = EFI_ACCESS_DENIED;
+ goto ForgetResolvedNodeId;
+ }
+
+ IsDirectory = (BOOLEAN)((FileInfo.Attribute & EFI_FILE_DIRECTORY) != 0);
+ if (IsDirectory) {
+ //
+ // If OpenForWriting is TRUE here, that's not passed to
+ // VirtioFsFuseOpenDir(); it does not affect the FUSE_OPENDIR request we
+ // send. OpenForWriting=TRUE will only permit attempts to delete, rename,
+ // flush (sync), and touch the directory.
+ //
+ Status = VirtioFsFuseOpenDir (VirtioFs, ResolvedNodeId, &NewFuseHandle);
+ } else {
+ Status = VirtioFsFuseOpen (VirtioFs, ResolvedNodeId, OpenForWriting,
+ &NewFuseHandle);
+ }
+ if (EFI_ERROR (Status)) {
+ goto ForgetResolvedNodeId;
+ }
+
+ *NodeId = ResolvedNodeId;
+ *FuseHandle = NewFuseHandle;
+ *NodeIsDirectory = IsDirectory;
+ return EFI_SUCCESS;
+
+ForgetResolvedNodeId:
+ VirtioFsFuseForget (VirtioFs, ResolvedNodeId);
+ return (Status == EFI_NOT_FOUND) ? EFI_DEVICE_ERROR : Status;
+}
+
+/**
+ Create a directory.
+
+ @param[in,out] VirtioFs The Virtio Filesystem device on which the directory
+ should be created.
+
+ @param[in] DirNodeId The inode number of the immediate parent directory
+ of the directory to create.
+
+ @param[in] Name The single-component filename of the directory to
+ create, under the immediate parent directory
+ identified by DirNodeId.
+
+ @param[out] NodeId The inode number of the directory created, returned
+ by the Virtio Filesystem device.
+
+ @param[out] FuseHandle The open handle to the directory created, returned
+ by the Virtio Filesystem device.
+
+ @retval EFI_SUCCESS The directory has been created successfully.
+
+ @return Errors propagated from underlying functions.
+**/
+STATIC
+EFI_STATUS
+CreateDirectory (
+ IN OUT VIRTIO_FS *VirtioFs,
+ IN UINT64 DirNodeId,
+ IN CHAR8 *Name,
+ OUT UINT64 *NodeId,
+ OUT UINT64 *FuseHandle
+ )
+{
+ EFI_STATUS Status;
+ UINT64 NewChildDirNodeId;
+ UINT64 NewFuseHandle;
+
+ Status = VirtioFsFuseMkDir (VirtioFs, DirNodeId, Name, &NewChildDirNodeId);
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ Status = VirtioFsFuseOpenDir (VirtioFs, NewChildDirNodeId, &NewFuseHandle);
+ if (EFI_ERROR (Status)) {
+ goto RemoveNewChildDir;
+ }
+
+ *NodeId = NewChildDirNodeId;
+ *FuseHandle = NewFuseHandle;
+ return EFI_SUCCESS;
+
+RemoveNewChildDir:
+ VirtioFsFuseRemoveFileOrDir (VirtioFs, DirNodeId, Name, TRUE /* IsDir */);
+ VirtioFsFuseForget (VirtioFs, NewChildDirNodeId);
+ return Status;
+}
+
+/**
+ Create a regular file.
+
+ @param[in,out] VirtioFs The Virtio Filesystem device on which the regular
+ file should be created.
+
+ @param[in] DirNodeId The inode number of the immediate parent directory
+ of the regular file to create.
+
+ @param[in] Name The single-component filename of the regular file to
+ create, under the immediate parent directory
+ identified by DirNodeId.
+
+ @param[out] NodeId The inode number of the regular file created,
+ returned by the Virtio Filesystem device.
+
+ @param[out] FuseHandle The open handle to the regular file created,
+ returned by the Virtio Filesystem device.
+
+ @retval EFI_SUCCESS The regular file has been created successfully.
+
+ @return Errors propagated from underlying functions.
+**/
+STATIC
+EFI_STATUS
+CreateRegularFile (
+ IN OUT VIRTIO_FS *VirtioFs,
+ IN UINT64 DirNodeId,
+ IN CHAR8 *Name,
+ OUT UINT64 *NodeId,
+ OUT UINT64 *FuseHandle
+ )
+{
+ return VirtioFsFuseOpenOrCreate (VirtioFs, DirNodeId, Name, NodeId,
+ FuseHandle);
+}
+
EFI_STATUS
EFIAPI
VirtioFsSimpleFileOpen (
@@ -18,5 +294,207 @@ VirtioFsSimpleFileOpen ( IN UINT64 Attributes
)
{
- return EFI_NO_MEDIA;
+ VIRTIO_FS_FILE *VirtioFsFile;
+ VIRTIO_FS *VirtioFs;
+ BOOLEAN OpenForWriting;
+ BOOLEAN PermitCreation;
+ BOOLEAN CreateDirectoryIfCreating;
+ VIRTIO_FS_FILE *NewVirtioFsFile;
+ EFI_STATUS Status;
+ CHAR8 *NewCanonicalPath;
+ BOOLEAN RootEscape;
+ UINT64 DirNodeId;
+ CHAR8 *LastComponent;
+ UINT64 NewNodeId;
+ UINT64 NewFuseHandle;
+ BOOLEAN NewNodeIsDirectory;
+
+ VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);
+ VirtioFs = VirtioFsFile->OwnerFs;
+
+ //
+ // Validate OpenMode.
+ //
+ switch (OpenMode) {
+ case EFI_FILE_MODE_READ:
+ OpenForWriting = FALSE;
+ PermitCreation = FALSE;
+ break;
+ case EFI_FILE_MODE_READ | EFI_FILE_MODE_WRITE:
+ OpenForWriting = TRUE;
+ PermitCreation = FALSE;
+ break;
+ case EFI_FILE_MODE_READ | EFI_FILE_MODE_WRITE | EFI_FILE_MODE_CREATE:
+ OpenForWriting = TRUE;
+ PermitCreation = TRUE;
+ break;
+ default:
+ return EFI_INVALID_PARAMETER;
+ }
+
+ //
+ // Validate the Attributes requested for the case when the file ends up being
+ // created, provided creation is permitted.
+ //
+ if (PermitCreation) {
+ if ((Attributes & ~EFI_FILE_VALID_ATTR) != 0) {
+ //
+ // Unknown attribute requested.
+ //
+ return EFI_INVALID_PARAMETER;
+ }
+
+ ASSERT (OpenForWriting);
+ if ((Attributes & EFI_FILE_READ_ONLY) != 0) {
+ DEBUG ((
+ DEBUG_ERROR,
+ ("%a: Label=\"%s\" CanonicalPathname=\"%a\" FileName=\"%s\" "
+ "OpenMode=0x%Lx Attributes=0x%Lx: nonsensical request to possibly "
+ "create a file marked read-only, for read-write access\n"),
+ __FUNCTION__,
+ VirtioFs->Label,
+ VirtioFsFile->CanonicalPathname,
+ FileName,
+ OpenMode,
+ Attributes
+ ));
+ return EFI_INVALID_PARAMETER;
+ }
+ CreateDirectoryIfCreating = (BOOLEAN)((Attributes &
+ EFI_FILE_DIRECTORY) != 0);
+ }
+
+ //
+ // Referring to a file relative to a regular file makes no sense (or at least
+ // it cannot be implemented consistently with how a file is referred to
+ // relative to a directory).
+ //
+ if (!VirtioFsFile->IsDirectory) {
+ DEBUG ((
+ DEBUG_ERROR,
+ ("%a: Label=\"%s\" CanonicalPathname=\"%a\" FileName=\"%s\": "
+ "nonsensical request to open a file or directory relative to a regular "
+ "file\n"),
+ __FUNCTION__,
+ VirtioFs->Label,
+ VirtioFsFile->CanonicalPathname,
+ FileName
+ ));
+ return EFI_INVALID_PARAMETER;
+ }
+
+ //
+ // Allocate the new VIRTIO_FS_FILE object.
+ //
+ NewVirtioFsFile = AllocatePool (sizeof *NewVirtioFsFile);
+ if (NewVirtioFsFile == NULL) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ //
+ // Create the canonical pathname at which the desired file is expected to
+ // exist.
+ //
+ Status = VirtioFsAppendPath (VirtioFsFile->CanonicalPathname, FileName,
+ &NewCanonicalPath, &RootEscape);
+ if (EFI_ERROR (Status)) {
+ goto FreeNewVirtioFsFile;
+ }
+ if (RootEscape) {
+ Status = EFI_ACCESS_DENIED;
+ goto FreeNewCanonicalPath;
+ }
+
+ //
+ // If the desired file is the root directory, just open the volume one more
+ // time, without looking up anything.
+ //
+ if (AsciiStrCmp (NewCanonicalPath, "/") == 0) {
+ FreePool (NewCanonicalPath);
+ FreePool (NewVirtioFsFile);
+ return OpenRootDirectory (VirtioFs, NewHandle, OpenForWriting);
+ }
+
+ //
+ // Split the new canonical pathname into most specific parent directory
+ // (given by DirNodeId) and last pathname component (i.e., immediate child
+ // within that parent directory).
+ //
+ Status = VirtioFsLookupMostSpecificParentDir (VirtioFs, NewCanonicalPath,
+ &DirNodeId, &LastComponent);
+ if (EFI_ERROR (Status)) {
+ goto FreeNewCanonicalPath;
+ }
+
+ //
+ // Try to open LastComponent directly under DirNodeId, as an existent regular
+ // file or directory.
+ //
+ Status = OpenExistentFileOrDirectory (VirtioFs, DirNodeId, LastComponent,
+ OpenForWriting, &NewNodeId, &NewFuseHandle, &NewNodeIsDirectory);
+ //
+ // If LastComponent could not be found under DirNodeId, but the request
+ // allows us to create a new entry, attempt creating the requested regular
+ // file or directory.
+ //
+ if (Status == EFI_NOT_FOUND && PermitCreation) {
+ ASSERT (OpenForWriting);
+ if (CreateDirectoryIfCreating) {
+ Status = CreateDirectory (VirtioFs, DirNodeId, LastComponent, &NewNodeId,
+ &NewFuseHandle);
+ } else {
+ Status = CreateRegularFile (VirtioFs, DirNodeId, LastComponent,
+ &NewNodeId, &NewFuseHandle);
+ }
+ NewNodeIsDirectory = CreateDirectoryIfCreating;
+ }
+
+ //
+ // Regardless of the branch taken, we're done with DirNodeId.
+ //
+ if (DirNodeId != VIRTIO_FS_FUSE_ROOT_DIR_NODE_ID) {
+ VirtioFsFuseForget (VirtioFs, DirNodeId);
+ }
+
+ if (EFI_ERROR (Status)) {
+ goto FreeNewCanonicalPath;
+ }
+
+ //
+ // Populate the new VIRTIO_FS_FILE object.
+ //
+ NewVirtioFsFile->Signature = VIRTIO_FS_FILE_SIG;
+ NewVirtioFsFile->SimpleFile.Revision = EFI_FILE_PROTOCOL_REVISION;
+ NewVirtioFsFile->SimpleFile.Open = VirtioFsSimpleFileOpen;
+ NewVirtioFsFile->SimpleFile.Close = VirtioFsSimpleFileClose;
+ NewVirtioFsFile->SimpleFile.Delete = VirtioFsSimpleFileDelete;
+ NewVirtioFsFile->SimpleFile.Read = VirtioFsSimpleFileRead;
+ NewVirtioFsFile->SimpleFile.Write = VirtioFsSimpleFileWrite;
+ NewVirtioFsFile->SimpleFile.GetPosition = VirtioFsSimpleFileGetPosition;
+ NewVirtioFsFile->SimpleFile.SetPosition = VirtioFsSimpleFileSetPosition;
+ NewVirtioFsFile->SimpleFile.GetInfo = VirtioFsSimpleFileGetInfo;
+ NewVirtioFsFile->SimpleFile.SetInfo = VirtioFsSimpleFileSetInfo;
+ NewVirtioFsFile->SimpleFile.Flush = VirtioFsSimpleFileFlush;
+ NewVirtioFsFile->IsDirectory = NewNodeIsDirectory;
+ NewVirtioFsFile->IsOpenForWriting = OpenForWriting;
+ NewVirtioFsFile->OwnerFs = VirtioFs;
+ NewVirtioFsFile->CanonicalPathname = NewCanonicalPath;
+ NewVirtioFsFile->NodeId = NewNodeId;
+ NewVirtioFsFile->FuseHandle = NewFuseHandle;
+
+ //
+ // One more file is now open for the filesystem.
+ //
+ InsertTailList (&VirtioFs->OpenFiles, &NewVirtioFsFile->OpenFilesEntry);
+
+ *NewHandle = &NewVirtioFsFile->SimpleFile;
+ return EFI_SUCCESS;
+
+FreeNewCanonicalPath:
+ FreePool (NewCanonicalPath);
+
+FreeNewVirtioFsFile:
+ FreePool (NewVirtioFsFile);
+
+ return Status;
}
|