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MdePkg/UefiLib: introduce EfiOpenFileByDevicePath()

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The EfiOpenFileByDevicePath() function centralizes functionality from

- MdeModulePkg/Universal/Disk/RamDiskDxe
- NetworkPkg/TlsAuthConfigDxe
- SecurityPkg/VariableAuthenticated/SecureBootConfigDxe
- ShellPkg/Library/UefiShellLib

unifying the implementation and fixing various bugs.

(Ray suggested that we eliminate the special handling of
EFI_FILE_MODE_CREATE in the "OpenMode" input parameter as well. We plan to
implement that separately, under
<https://bugzilla.tianocore.org/show_bug.cgi?id=1074>.)

Cc: Chao Zhang <chao.b.zhang@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Jaben Carsey <jaben.carsey@intel.com>
Cc: Jiaxin Wu <jiaxin.wu@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Roman Bacik <roman.bacik@broadcom.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Siyuan Fu <siyuan.fu@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1008
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
This commit is contained in:
Laszlo Ersek
2018-07-18 17:07:03 +02:00
parent 52047be024
commit 768b611136
3 changed files with 316 additions and 0 deletions
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88
MdePkg/Include/Library/UefiLib.h
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@@ -33,6 +33,8 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
#include <Protocol/DriverDiagnostics.h>
#include <Protocol/DriverDiagnostics2.h>
#include <Protocol/GraphicsOutput.h>
#include <Protocol/DevicePath.h>
#include <Protocol/SimpleFileSystem.h>
#include <Library/BaseLib.h>
@@ -1520,4 +1522,90 @@ EfiLocateProtocolBuffer (
OUT UINTN *NoProtocols,
OUT VOID ***Buffer
);
/**
Open or create a file or directory, possibly creating the chain of
directories leading up to the directory.
EfiOpenFileByDevicePath() first locates EFI_SIMPLE_FILE_SYSTEM_PROTOCOL on
FilePath, and opens the root directory of that filesystem with
EFI_SIMPLE_FILE_SYSTEM_PROTOCOL.OpenVolume().
On the remaining device path, the longest initial sequence of
FILEPATH_DEVICE_PATH nodes is node-wise traversed with
EFI_FILE_PROTOCOL.Open(). For the pathname fragment specified by each
traversed FILEPATH_DEVICE_PATH node, EfiOpenFileByDevicePath() first masks
EFI_FILE_MODE_CREATE out of OpenMode, and passes 0 for Attributes. If
EFI_FILE_PROTOCOL.Open() fails, and OpenMode includes EFI_FILE_MODE_CREATE,
then the operation is retried with the caller's OpenMode and Attributes
unmodified.
(As a consequence, if OpenMode includes EFI_FILE_MODE_CREATE, and Attributes
includes EFI_FILE_DIRECTORY, and each FILEPATH_DEVICE_PATH specifies a single
pathname component, then EfiOpenFileByDevicePath() ensures that the specified
series of subdirectories exist on return.)
The EFI_FILE_PROTOCOL identified by the last FILEPATH_DEVICE_PATH node is
output to the caller; intermediate EFI_FILE_PROTOCOL instances are closed. If
there are no FILEPATH_DEVICE_PATH nodes past the node that identifies the
filesystem, then the EFI_FILE_PROTOCOL of the root directory of the
filesystem is output to the caller. If a device path node that is different
from FILEPATH_DEVICE_PATH is encountered relative to the filesystem, the
traversal is stopped with an error, and a NULL EFI_FILE_PROTOCOL is output.
@param[in,out] FilePath On input, the device path to the file or directory
to open or create. The caller is responsible for
ensuring that the device path pointed-to by FilePath
is well-formed. On output, FilePath points one past
the last node in the original device path that has
been successfully processed. FilePath is set on
output even if EfiOpenFileByDevicePath() returns an
error.
@param[out] File On error, File is set to NULL. On success, File is
set to the EFI_FILE_PROTOCOL of the root directory
of the filesystem, if there are no
FILEPATH_DEVICE_PATH nodes in FilePath; otherwise,
File is set to the EFI_FILE_PROTOCOL identified by
the last node in FilePath.
@param[in] OpenMode The OpenMode parameter to pass to
EFI_FILE_PROTOCOL.Open(). For each
FILEPATH_DEVICE_PATH node in FilePath,
EfiOpenFileByDevicePath() first opens the specified
pathname fragment with EFI_FILE_MODE_CREATE masked
out of OpenMode and with Attributes set to 0, and
only retries the operation with EFI_FILE_MODE_CREATE
unmasked and Attributes propagated if the first open
attempt fails.
@param[in] Attributes The Attributes parameter to pass to
EFI_FILE_PROTOCOL.Open(), when EFI_FILE_MODE_CREATE
is propagated unmasked in OpenMode.
@retval EFI_SUCCESS The file or directory has been opened or
created.
@retval EFI_INVALID_PARAMETER FilePath is NULL; or File is NULL; or FilePath
contains a device path node, past the node
that identifies
EFI_SIMPLE_FILE_SYSTEM_PROTOCOL, that is not a
FILEPATH_DEVICE_PATH node.
@retval EFI_OUT_OF_RESOURCES Memory allocation failed.
@return Error codes propagated from the
LocateDevicePath() and OpenProtocol() boot
services, and from the
EFI_SIMPLE_FILE_SYSTEM_PROTOCOL.OpenVolume()
and EFI_FILE_PROTOCOL.Open() member functions.
**/
EFI_STATUS
EFIAPI
EfiOpenFileByDevicePath (
IN OUT EFI_DEVICE_PATH_PROTOCOL **FilePath,
OUT EFI_FILE_PROTOCOL **File,
IN UINT64 OpenMode,
IN UINT64 Attributes
);
#endif