[PATCH 1/2] staging/RedfishClientPkg: Add EDKII ETag driver


Abner Chang
 

Implement EDKII ETag protocol to manipulate ETag of
HTTP content.

Signed-off-by: Nickle Wang <nickle.wang@hpe.com>
Cc: Abner Chang <abner.chang@hpe.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
---
.../RedfishETagDxe/RedfishETagDxe.inf | 45 +
.../Protocol/EdkIIRedfishETagProtocol.h | 76 ++
.../RedfishETagDxe/RedfishETagDxe.h | 70 ++
.../RedfishETagDxe/RedfishETagDxe.c | 774 ++++++++++++++++++
4 files changed, 965 insertions(+)
create mode 100644 RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.inf
create mode 100644 RedfishClientPkg/Include/Protocol/EdkIIRedfishETagProtocol.h
create mode 100644 RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.h
create mode 100644 RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.c

diff --git a/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.inf b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.inf
new file mode 100644
index 00000000000..4315b1eaa5f
--- /dev/null
+++ b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.inf
@@ -0,0 +1,45 @@
+## @file
+#
+# (C) Copyright 2021 Hewlett Packard Enterprise Development LP<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+ INF_VERSION = 0x0001000b
+ BASE_NAME = RedfishETagDxe
+ FILE_GUID = F7BB0BB2-9796-485F-9F00-C0EB47E9F92B
+ MODULE_TYPE = DXE_DRIVER
+ VERSION_STRING = 1.0
+ ENTRY_POINT = RedfishETagDriverEntryPoint
+ UNLOAD_IMAGE = RedfishETagDriverUnload
+
+[Packages]
+ MdePkg/MdePkg.dec
+ MdeModulePkg/MdeModulePkg.dec
+ RedfishPkg/RedfishPkg.dec
+ RedfishClientPkg/RedfishClientPkg.dec
+
+[Sources]
+ RedfishETagDxe.h
+ RedfishETagDxe.c
+
+[LibraryClasses]
+ BaseLib
+ BaseMemoryLib
+ DebugLib
+ MemoryAllocationLib
+ UefiLib
+ UefiBootServicesTableLib
+ UefiRuntimeServicesTableLib
+ UefiDriverEntryPoint
+
+[Protocols]
+ gEdkIIRedfishETagProtocolGuid ## PRODUCED ##
+
+[Guids]
+ gEfiEventExitBootServicesGuid ## CONSUMES ## Event
+
+[Depex]
+ TRUE
diff --git a/RedfishClientPkg/Include/Protocol/EdkIIRedfishETagProtocol.h b/RedfishClientPkg/Include/Protocol/EdkIIRedfishETagProtocol.h
new file mode 100644
index 00000000000..3cbced44eb7
--- /dev/null
+++ b/RedfishClientPkg/Include/Protocol/EdkIIRedfishETagProtocol.h
@@ -0,0 +1,76 @@
+/** @file
+ This file defines the EDKII_REDFISH_FEATURE_PROTOCOL interface.
+
+ (C) Copyright 2021 Hewlett Packard Enterprise Development LP<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef EDKII_REDFISH_ETAG_PROTOCOL_H_
+#define EDKII_REDFISH_ETAG_PROTOCOL_H_
+
+typedef struct _EDKII_REDFISH_ETAG_PROTOCOL EDKII_REDFISH_ETAG_PROTOCOL;
+
+/**
+ Get ETag string by given URI
+
+ @param[in] This Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+ @param[in] Uri Target URI to search.
+ @param[out] ETag The ETag string to corresponding URI.
+
+ @retval EFI_SUCCESS The ETag is found successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter is given.
+
+**/
+typedef
+EFI_STATUS
+(EFIAPI *EDKII_REDFISH_ETAG_PROTOCOL_GET) (
+ IN EDKII_REDFISH_ETAG_PROTOCOL *This,
+ IN CHAR8 *Uri,
+ OUT CHAR8 **ETag
+ );
+
+/**
+ Keep ETag string which maps to given Uri.
+
+ @param[in] This Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+ @param[in] Uri The target Uri which related to ETag.
+ @param[in] ETag The ETag to add. If ETag is NULL, the record of correspoonding URI will be removed.
+
+ @retval EFI_SUCCESS This handler has been stoped successfully.
+ @retval Others Some error happened.
+
+**/
+typedef
+EFI_STATUS
+(EFIAPI *EDKII_REDFISH_ETAG_PROTOCOL_SET) (
+ IN EDKII_REDFISH_ETAG_PROTOCOL *This,
+ IN CHAR8 *Uri,
+ IN CHAR8 *ETag
+ );
+
+/**
+ Refresh the ETag database and save database to variable.
+
+ @param[in] This Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+
+ @retval EFI_SUCCESS This handler has been stoped successfully.
+ @retval Others Some error happened.
+
+**/
+typedef
+EFI_STATUS
+(EFIAPI *EDKII_REDFISH_ETAG_PROTOCOL_FLUSH) (
+ IN EDKII_REDFISH_ETAG_PROTOCOL *This
+ );
+
+struct _EDKII_REDFISH_ETAG_PROTOCOL {
+ EDKII_REDFISH_ETAG_PROTOCOL_GET Get;
+ EDKII_REDFISH_ETAG_PROTOCOL_SET Set;
+ EDKII_REDFISH_ETAG_PROTOCOL_FLUSH Flush;
+};
+
+extern EFI_GUID gEdkIIRedfishETagProtocolGuid;
+
+#endif
diff --git a/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.h b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.h
new file mode 100644
index 00000000000..c4465743133
--- /dev/null
+++ b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.h
@@ -0,0 +1,70 @@
+/** @file
+ Common header file for RedfishETagDxe driver.
+
+ (C) Copyright 2021 Hewlett Packard Enterprise Development LP<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef REDFISH_ETAG_DXE_H_
+#define REDFISH_ETAG_DXE_H_
+
+#include <Uefi.h>
+
+//
+// Libraries
+//
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiDriverEntryPoint.h>
+#include <Library/UefiLib.h>
+#include <Library/UefiRuntimeServicesTableLib.h>
+
+#include <Protocol/EdkIIRedfishETagProtocol.h>
+
+#include <Guid/VariableFormat.h>
+
+#define ETAG_VARIABLE_NAME L"RedfishETag"
+#define IS_EMPTY_STRING(a) ((a) == NULL || (a)[0] == '\0')
+#define ETAG_DEBUG_ENABLED 0x00
+
+//
+// Definition of REDFISH_ETAG_RECORD
+//
+typedef struct {
+ LIST_ENTRY List;
+ CHAR8 *Uri;
+ CHAR8 *ETag;
+ UINTN Size;
+} REDFISH_ETAG_RECORD;
+
+#define REDFISH_ETAG_RECORD_FROM_LIST(a) BASE_CR (a, REDFISH_ETAG_RECORD, List)
+
+//
+// Definition of REDFISH_ETAG_LIST
+//
+typedef struct {
+ LIST_ENTRY Listheader;
+ UINTN TotalSize;
+ UINTN Count;
+} REDFISH_ETAG_LIST;
+
+//
+// Definition of REDFISH_ETAG_PRIVATE_DATA
+//
+typedef struct {
+ EFI_HANDLE ImageHandle;
+ REDFISH_ETAG_LIST ETagList;
+ EDKII_REDFISH_ETAG_PROTOCOL Protocol;
+ EFI_STRING VariableName;
+ EFI_EVENT Event;
+} REDFISH_ETAG_PRIVATE_DATA;
+
+#define REDFISH_ETAG_PRIVATE_FROM_THIS(a) BASE_CR (a, REDFISH_ETAG_PRIVATE_DATA, Protocol)
+
+#endif
diff --git a/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.c b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.c
new file mode 100644
index 00000000000..349175340d4
--- /dev/null
+++ b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.c
@@ -0,0 +1,774 @@
+/** @file
+
+ (C) Copyright 2021 Hewlett Packard Enterprise Development LP<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "RedfishETagDxe.h"
+
+REDFISH_ETAG_PRIVATE_DATA *mRedfishETagPrivate = NULL;
+
+/**
+ Release REDFISH_ETAG_RECORD resource
+
+ @param[in] Record Pointer to REDFISH_ETAG_RECORD instance
+
+ @retval EFI_SUCCESS REDFISH_ETAG_RECORD is released successfully.
+ @retval EFI_INVALID_PARAMETER Record is NULL
+
+**/
+EFI_STATUS
+ReleaseETagRecord (
+ IN REDFISH_ETAG_RECORD *Record
+ )
+{
+ if (Record == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (Record->Uri != NULL) {
+ FreePool (Record->Uri);
+ }
+
+ if (Record->ETag != NULL) {
+ FreePool (Record->ETag);
+ }
+
+ FreePool (Record);
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Create new Etag resource.
+
+ @param[in] Uri The URI string matching to this ETAG.
+ @param[in] ETag ETAG string.
+
+ @retval REDFISH_ETAG_RECORD * Pointer to newly created ETAG.
+ @retval NULL No memory available.
+
+**/
+REDFISH_ETAG_RECORD *
+NewETagRecord (
+ IN CHAR8 *Uri,
+ IN CHAR8 *ETag
+ )
+{
+ REDFISH_ETAG_RECORD *NewRecord;
+ UINTN Size;
+
+ if (IS_EMPTY_STRING (Uri) || IS_EMPTY_STRING (ETag)) {
+ return NULL;
+ }
+
+ NewRecord = AllocateZeroPool (sizeof (REDFISH_ETAG_RECORD));
+ if (NewRecord == NULL) {
+ return NULL;
+ }
+
+ Size = AsciiStrSize (Uri);
+ NewRecord->Uri = AllocateCopyPool (Size, Uri);
+ if (NewRecord->Uri == NULL) {
+ goto ON_ERROR;
+ }
+
+ NewRecord->Size = Size;
+ Size = AsciiStrSize (ETag);
+ NewRecord->ETag = AllocateCopyPool (Size, ETag);
+ if (NewRecord->ETag == NULL) {
+ goto ON_ERROR;
+ }
+
+ NewRecord->Size += Size;
+ return NewRecord;
+
+ON_ERROR:
+
+ if (NewRecord != NULL) {
+ ReleaseETagRecord (NewRecord);
+ }
+
+ return NULL;
+}
+
+/**
+ Add new ETAG by given URI and ETAG string to specify List.
+
+ @param[in] List Target ETAG list to add.
+ @param[in] Uri The URI string matching to this ETAG.
+ @param[in] ETag ETAG string.
+
+ @retval EFI_SUCCESS ETAG recourd is added.
+ @retval Others Fail to add ETAG.
+
+**/
+EFI_STATUS
+AddETagRecord (
+ IN REDFISH_ETAG_LIST *List,
+ IN CHAR8 *Uri,
+ IN CHAR8 *ETag
+ )
+{
+ REDFISH_ETAG_RECORD *NewRecord;
+
+ if (List == NULL || IS_EMPTY_STRING (Uri) || IS_EMPTY_STRING (ETag)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ NewRecord = NewETagRecord (Uri, ETag);
+ if (NewETagRecord == NULL) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ InsertTailList (&List->Listheader, &NewRecord->List);
+ ++List->Count;
+ List->TotalSize += NewRecord->Size;
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Delete an ETAG by given ETAG instance.
+
+ @param[in] List Target ETAG list to be removed.
+ @param[in] Record Pointer to the instance to be deleted.
+
+ @retval EFI_SUCCESS ETAG recourd is removed.
+ @retval Others Fail to add ETAG.
+
+**/
+EFI_STATUS
+DeleteETagRecord (
+ IN REDFISH_ETAG_LIST *List,
+ IN REDFISH_ETAG_RECORD *Record
+ )
+{
+ if (List == NULL || Record == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ RemoveEntryList (&Record->List);
+ --List->Count;
+ List->TotalSize -= Record->Size;
+
+ return ReleaseETagRecord (Record);
+}
+
+/**
+ Search on given ListHeader for given URI string.
+
+ @param[in] ListHeader Target list to search.
+ @param[in] Uri Target URI to search.
+
+ @retval REDFISH_ETAG_RECORD Target ETAG is found.
+ @retval NULL No ETAG with given URI is found.
+
+**/
+REDFISH_ETAG_RECORD *
+FindETagRecord (
+ IN LIST_ENTRY *ListHeader,
+ IN CHAR8 *Uri
+ )
+{
+ LIST_ENTRY *List;
+ REDFISH_ETAG_RECORD *Record;
+
+ if (IsListEmpty (ListHeader)) {
+ return NULL;
+ }
+
+ Record = NULL;
+ List = GetFirstNode (ListHeader);
+ while (!IsNull (ListHeader, List)) {
+ Record = REDFISH_ETAG_RECORD_FROM_LIST (List);
+
+ if (AsciiStrCmp (Record->Uri, Uri) == 0) {
+ return Record;
+ }
+
+ List = GetNextNode (ListHeader, List);
+ }
+
+ return NULL;
+}
+
+#if ETAG_DEBUG_ENABLED
+/**
+ Debug output the ETAG list.
+
+ @param[in] ETagList Target list to dump
+ @param[in] Msg Debug message string.
+
+ @retval EFI_SUCCESS Debug dump finished.
+ @retval EFI_INVALID_PARAMETER ETagList is NULL.
+
+**/
+EFI_STATUS
+DumpETagList (
+ IN REDFISH_ETAG_LIST *ETagList,
+ IN EFI_STRING Msg
+ )
+{
+ LIST_ENTRY *List;
+ REDFISH_ETAG_RECORD *Record;
+
+ if (ETagList == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (!IS_EMPTY_STRING (Msg)) {
+ DEBUG ((DEBUG_ERROR, "%s\n", Msg));
+ }
+
+ if (IsListEmpty (&ETagList->Listheader)) {
+ DEBUG ((DEBUG_INFO, "ETag list is empty\n"));
+ return EFI_NOT_FOUND;
+ }
+
+ DEBUG ((DEBUG_INFO, "Count: %d Total Size: %d\n", ETagList->Count, ETagList->TotalSize));
+ Record = NULL;
+ List = GetFirstNode (&ETagList->Listheader);
+ while (!IsNull (&ETagList->Listheader, List)) {
+ Record = REDFISH_ETAG_RECORD_FROM_LIST (List);
+
+ DEBUG ((DEBUG_INFO, "ETag: %a Uri: %a Size: %d\n", Record->ETag, Record->Uri, Record->Size));
+
+ List = GetNextNode (&ETagList->Listheader, List);
+ }
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Debug output raw data buffer.
+
+ @param[in] Buffer Debug output data buffer.
+ @param[in] BufferSize The size of Buffer in byte.
+
+ @retval EFI_SUCCESS Debug dump finished.
+ @retval EFI_INVALID_PARAMETER Buffer is NULL.
+
+**/
+EFI_STATUS
+DumpRawBuffer (
+ IN CHAR8 *Buffer,
+ IN UINTN BufferSize
+ )
+{
+ UINTN Index;
+
+ if (Buffer == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ Index = 0;
+
+ DEBUG ((DEBUG_ERROR, "Buffer size: %d\n", BufferSize));
+ while (Buffer[Index] != '\0') {
+ DEBUG ((DEBUG_ERROR, "(%d) %c ", (Index + 1), Buffer[Index]));
+
+ ++Index;
+ }
+ DEBUG ((DEBUG_ERROR, "\n"));
+
+ return EFI_SUCCESS;
+}
+#endif
+
+/**
+ Release all ETag from list.
+
+ @param[in] ETagList The list to be released.
+
+ @retval EFI_SUCCESS All etag is released.
+ @retval EFI_INVALID_PARAMETER ETagList is NULL.
+
+**/
+EFI_STATUS
+ReleaseETagList (
+ IN REDFISH_ETAG_LIST *ETagList
+ )
+{
+ LIST_ENTRY *List;
+ LIST_ENTRY *Next;
+ REDFISH_ETAG_RECORD *Record;
+
+ if (ETagList == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (IsListEmpty (&ETagList->Listheader)) {
+ return EFI_SUCCESS;
+ }
+
+ Record = NULL;
+ Next = NULL;
+ List = GetFirstNode (&ETagList->Listheader);
+ while (!IsNull (&ETagList->Listheader, List)) {
+ Record = REDFISH_ETAG_RECORD_FROM_LIST (List);
+ Next = GetNextNode (&ETagList->Listheader, List);
+
+ DeleteETagRecord (ETagList, Record);
+
+ List = Next;
+ }
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Save etag in list to UEFI variable.
+
+ @param[in] ETagList The list to be saved.
+ @param[in] VariableName The UEFI variable name.
+
+ @retval EFI_SUCCESS All etag is saved.
+ @retval EFI_INVALID_PARAMETER VariableName or ETagList is NULL.
+
+**/
+EFI_STATUS
+SaveETagList (
+ IN REDFISH_ETAG_LIST *ETagList,
+ IN EFI_STRING VariableName
+ )
+{
+ LIST_ENTRY *List;
+ REDFISH_ETAG_RECORD *Record;
+ CHAR8 *VarData;
+ VOID *Data;
+ CHAR8 *Seeker;
+ UINTN VarSize;
+ UINTN StrSize;
+ EFI_STATUS Status;
+
+ if (ETagList == NULL || IS_EMPTY_STRING (VariableName)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (IsListEmpty (&ETagList->Listheader)) {
+ return EFI_SUCCESS;
+ }
+
+ //
+ // Caculate the total size we need to keep ETag list.
+ //
+ VarSize = ETagList->TotalSize + 1; // terminator character
+ VarData = AllocateZeroPool (VarSize);
+ if (VarData == NULL) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ Seeker = VarData;
+ Record = NULL;
+ List = GetFirstNode (&ETagList->Listheader);
+ while (!IsNull (&ETagList->Listheader, List)) {
+ Record = REDFISH_ETAG_RECORD_FROM_LIST (List);
+
+ StrSize = AsciiStrSize (Record->Uri);
+ CopyMem (Seeker, Record->Uri, StrSize);
+
+ Seeker += (StrSize - 1);
+ *Seeker = '|';
+ ++Seeker;
+
+ StrSize = AsciiStrSize (Record->ETag);
+ CopyMem (Seeker, Record->ETag, StrSize);
+
+ Seeker += (StrSize - 1);
+ *Seeker = '\n';
+
+ ++Seeker;
+
+ List = GetNextNode (&ETagList->Listheader, List);;
+ }
+
+ *Seeker = '\0';
+
+#if ETAG_DEBUG_ENABLED
+ DumpRawBuffer (VarData, VarSize);
+#endif
+
+ ASSERT (((UINTN)Seeker - (UINTN)VarData + 1) == VarSize);
+
+ //
+ // Check if variable exists already. If yes, remove it first.
+ //
+ Status = GetVariable2 (
+ VariableName,
+ &gEfiCallerIdGuid,
+ (VOID *)&Data,
+ NULL
+ );
+ if (!EFI_ERROR (Status)) {
+ FreePool (Data);
+ gRT->SetVariable (VariableName, &gEfiCallerIdGuid, VARIABLE_ATTRIBUTE_NV_BS, 0, NULL);
+ }
+
+
+ return gRT->SetVariable (VariableName, &gEfiCallerIdGuid, VARIABLE_ATTRIBUTE_NV_BS, VarSize, (VOID *)VarData);
+}
+
+/**
+ Read etag from UEFI variable if it exists.
+
+ @param[in] ETagList The list to be loaded.
+ @param[in] VariableName The UEFI variable name.
+
+ @retval EFI_SUCCESS All etag is read successfully.
+ @retval EFI_INVALID_PARAMETER VariableName or ETagList is NULL.
+ @retval EFI_NOT_FOUND No etag is found on UEFI variable.
+
+**/
+EFI_STATUS
+InitialETagList (
+ IN REDFISH_ETAG_LIST *ETagList,
+ IN EFI_STRING VariableName
+ )
+{
+ CHAR8 *VarData;
+ CHAR8 *UriPointer;
+ CHAR8 *ETagPointer;
+ CHAR8 *Seeker;
+ UINTN VariableSize;
+ EFI_STATUS Status;
+
+ if (ETagList == NULL || IS_EMPTY_STRING (VariableName)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ //
+ // Check if variable exists already.
+ //
+ Status = GetVariable2 (
+ VariableName,
+ &gEfiCallerIdGuid,
+ (VOID *)&VarData,
+ &VariableSize
+ );
+ if (EFI_ERROR (Status)) {
+ return EFI_NOT_FOUND;
+ }
+
+ Seeker = VarData;
+ UriPointer = VarData;
+ ETagPointer = VarData;
+ while (*Seeker != '\0') {
+
+ //
+ // Find URI
+ //
+ Seeker = AsciiStrStr (UriPointer, "|");
+ if (Seeker == NULL) {
+ DEBUG ((DEBUG_ERROR, "%a, data corrupted\n", __FUNCTION__));
+ Status = EFI_DEVICE_ERROR;
+ goto ON_ERROR;
+ }
+
+ *Seeker = '\0';
+ ETagPointer = ++Seeker;
+
+ //
+ // Find ETAG
+ //
+ Seeker = AsciiStrStr (ETagPointer, "\n");
+ if (Seeker == NULL) {
+ DEBUG ((DEBUG_ERROR, "%a, data corrupted\n", __FUNCTION__));
+ Status = EFI_DEVICE_ERROR;
+ goto ON_ERROR;
+ }
+
+ *Seeker = '\0';
+
+ AddETagRecord (ETagList, UriPointer, ETagPointer);
+
+ UriPointer = ++Seeker;
+ }
+
+#if ETAG_DEBUG_ENABLED
+ DumpETagList (ETagList, L"Initial ETag List from Variable");
+#endif
+
+ Status = EFI_SUCCESS;
+
+ON_ERROR:
+
+ FreePool (VarData);
+
+ return Status;
+}
+
+/**
+ Get ETag string by given URI
+
+ @param[in] This Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+ @param[in] Uri Target URI to search.
+ @param[out] ETag The ETag string to corresponding URI.
+
+ @retval EFI_SUCCESS The ETag is found successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter is given.
+
+**/
+EFI_STATUS
+RedfishETagGet (
+ IN EDKII_REDFISH_ETAG_PROTOCOL *This,
+ IN CHAR8 *Uri,
+ OUT CHAR8 **ETag
+ )
+{
+ REDFISH_ETAG_RECORD *Target;
+ REDFISH_ETAG_PRIVATE_DATA *Private;
+
+ if (This == NULL || IS_EMPTY_STRING (Uri) || ETag == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ Private = REDFISH_ETAG_PRIVATE_FROM_THIS (This);
+
+ *ETag = NULL;
+
+ Target = FindETagRecord (&Private->ETagList.Listheader, Uri);
+ if (Target == NULL) {
+ return EFI_NOT_FOUND;
+ }
+
+ *ETag = AllocateCopyPool (AsciiStrSize (Target->ETag), Target->ETag);
+
+ return EFI_SUCCESS;
+}
+
+
+/**
+ Keep ETag string which maps to given Uri.
+
+ @param[in] This Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+ @param[in] Uri The target Uri which related to ETag.
+ @param[in] ETag The ETag to add. If ETag is NULL, the record of correspoonding URI will be removed.
+
+ @retval EFI_SUCCESS This handler has been stoped successfully.
+ @retval Others Some error happened.
+
+**/
+EFI_STATUS
+RedfishETagSet (
+ IN EDKII_REDFISH_ETAG_PROTOCOL *This,
+ IN CHAR8 *Uri,
+ IN CHAR8 *ETag OPTIONAL
+ )
+{
+ REDFISH_ETAG_RECORD *Target;
+ REDFISH_ETAG_PRIVATE_DATA *Private;
+ EFI_STATUS Status;
+
+ if (This == NULL || IS_EMPTY_STRING (Uri)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ Private = REDFISH_ETAG_PRIVATE_FROM_THIS (This);
+
+ Status = EFI_NOT_FOUND;
+ Target = FindETagRecord (&Private->ETagList.Listheader, Uri);
+ if (Target != NULL) {
+ //
+ // Remove old one and create new one.
+ //
+ Status = DeleteETagRecord (&Private->ETagList, Target);
+ }
+
+ //
+ // When ETag is NULL, it means that we want to remov this record.
+ //
+ if (ETag == NULL) {
+ return Status;
+ }
+
+ return AddETagRecord (&Private->ETagList, Uri, ETag);
+}
+
+/**
+ Refresh the ETag database and save database to variable.
+
+ @param[in] This Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+
+ @retval EFI_SUCCESS This handler has been stoped successfully.
+ @retval Others Some error happened.
+
+**/
+EFI_STATUS
+RedfishETagFlush (
+ IN EDKII_REDFISH_ETAG_PROTOCOL *This
+ )
+{
+ REDFISH_ETAG_PRIVATE_DATA *Private;
+ EFI_STATUS Status;
+
+ if (This == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ Private = REDFISH_ETAG_PRIVATE_FROM_THIS (This);
+
+ Status = SaveETagList (&Private->ETagList, Private->VariableName);
+ if (EFI_ERROR (Status)) {
+ DEBUG ((DEBUG_ERROR, "%a, save ETag list to variable: %s failed: %r\n", __FUNCTION__, Private->VariableName, Status));
+ }
+
+ return Status;
+}
+
+/**
+ Callback function executed when the ExitBootService event group is signaled.
+
+ @param[in] Event Event whose notification function is being invoked.
+ @param[out] Context Pointer to the Context buffer
+
+**/
+VOID
+EFIAPI
+RedfishETagOnExitBootService (
+ IN EFI_EVENT Event,
+ OUT VOID *Context
+ )
+{
+ //
+ // Memory is about to be released. Keep list into variable.
+ //
+ RedfishETagFlush (&mRedfishETagPrivate->Protocol);
+}
+
+/**
+ Unloads an image.
+
+ @param[in] ImageHandle Handle that identifies the image to be unloaded.
+
+ @retval EFI_SUCCESS The image has been unloaded.
+ @retval EFI_INVALID_PARAMETER ImageHandle is not a valid image handle.
+
+**/
+EFI_STATUS
+EFIAPI
+RedfishETagDriverUnload (
+ IN EFI_HANDLE ImageHandle
+ )
+{
+ EFI_STATUS Status;
+
+ if (mRedfishETagPrivate != NULL) {
+
+ Status = gBS->UninstallProtocolInterface (
+ mRedfishETagPrivate->ImageHandle,
+ &gEdkIIRedfishETagProtocolGuid,
+ (VOID*)&mRedfishETagPrivate->Protocol
+ );
+ if (EFI_ERROR (Status)) {
+ DEBUG ((DEBUG_ERROR, "%a, can not uninstall gEdkIIRedfishETagProtocolGuid: %r\n", __FUNCTION__, Status));
+ ASSERT (FALSE);
+ }
+
+ ReleaseETagList (&mRedfishETagPrivate->ETagList);
+
+ if (mRedfishETagPrivate->VariableName != NULL) {
+ FreePool (mRedfishETagPrivate->VariableName);
+ }
+
+ if (mRedfishETagPrivate->Event != NULL) {
+ gBS->CloseEvent (mRedfishETagPrivate->Event);
+ }
+
+ FreePool (mRedfishETagPrivate);
+ mRedfishETagPrivate = NULL;
+ }
+
+
+ return EFI_SUCCESS;
+}
+
+//
+// EDKII_REDFISH_ETAG_PROTOCOL.
+//
+EDKII_REDFISH_ETAG_PROTOCOL mRedfishETagProtocol = {
+ RedfishETagGet,
+ RedfishETagSet,
+ RedfishETagFlush
+};
+
+/**
+ This is the declaration of an EFI image entry point. This entry point is
+ the same for UEFI Applications, UEFI OS Loaders, and UEFI Drivers including
+ both device drivers and bus drivers.
+
+ @param[in] ImageHandle The firmware allocated handle for the UEFI image.
+ @param[in] SystemTable A pointer to the EFI System Table.
+
+ @retval EFI_SUCCESS The operation completed successfully.
+ @retval Others An unexpected error occurred.
+**/
+EFI_STATUS
+EFIAPI
+RedfishETagDriverEntryPoint (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ EFI_STATUS Status;
+
+ mRedfishETagPrivate = AllocateZeroPool (sizeof (REDFISH_ETAG_PRIVATE_DATA));
+ if (mRedfishETagPrivate == NULL) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ InitializeListHead (&mRedfishETagPrivate->ETagList.Listheader);
+ mRedfishETagPrivate->VariableName = AllocateCopyPool (StrSize (ETAG_VARIABLE_NAME), ETAG_VARIABLE_NAME);
+ if (mRedfishETagPrivate->VariableName == NULL) {
+ goto ON_ERROR;
+ }
+
+ mRedfishETagPrivate->ImageHandle = ImageHandle;
+ CopyMem (&mRedfishETagPrivate->Protocol, &mRedfishETagProtocol, sizeof (EDKII_REDFISH_ETAG_PROTOCOL));
+
+ Status = gBS->InstallProtocolInterface (
+ &ImageHandle,
+ &gEdkIIRedfishETagProtocolGuid,
+ EFI_NATIVE_INTERFACE,
+ (VOID*)&mRedfishETagPrivate->Protocol
+ );
+ if (EFI_ERROR (Status)) {
+ DEBUG ((DEBUG_ERROR, "%a, can not install gEdkIIRedfishETagProtocolGuid: %r\n", __FUNCTION__, Status));
+ ASSERT (FALSE);
+ goto ON_ERROR;
+ }
+
+ //
+ // Create Exit Boot Service event.
+ //
+ Status = gBS->CreateEventEx (
+ EVT_NOTIFY_SIGNAL,
+ TPL_CALLBACK,
+ RedfishETagOnExitBootService,
+ NULL,
+ &gEfiEventExitBootServicesGuid,
+ &mRedfishETagPrivate->Event
+ );
+ if (EFI_ERROR (Status)) {
+ DEBUG ((DEBUG_ERROR, "%a: Fail to register Exit Boot Service event.", __FUNCTION__));
+ goto ON_ERROR;
+ }
+
+ //
+ // Read existing record from variable.
+ //
+ Status = InitialETagList (&mRedfishETagPrivate->ETagList, mRedfishETagPrivate->VariableName);
+ if (EFI_ERROR (Status)) {
+ DEBUG ((DEBUG_INFO, "%a, Initial ETag List: %r\n", __FUNCTION__, Status));
+ }
+
+ return EFI_SUCCESS;
+
+ON_ERROR:
+
+ RedfishETagDriverUnload (ImageHandle);
+
+ return Status;
+}
--
2.21.0.windows.1


Nickle Wang
 

Reviewed-by: Nickle Wang <nickle.wang@...>

Thanks,
Nickle


From: Chang, Abner (HPS SW/FW Technologist) <abner.chang@...>
Sent: Monday, October 25, 2021 15:41
To: devel@edk2.groups.io <devel@edk2.groups.io>
Cc: Wang, Nickle (HPS SW) <nickle.wang@...>; Liming Gao <gaoliming@...>
Subject: [PATCH 1/2] staging/RedfishClientPkg: Add EDKII ETag driver
 
Implement EDKII ETag protocol to manipulate ETag of
HTTP content.

Signed-off-by: Nickle Wang <nickle.wang@...>
Cc: Abner Chang <abner.chang@...>
Cc: Liming Gao <gaoliming@...>
---
 .../RedfishETagDxe/RedfishETagDxe.inf         |  45 +
 .../Protocol/EdkIIRedfishETagProtocol.h       |  76 ++
 .../RedfishETagDxe/RedfishETagDxe.h           |  70 ++
 .../RedfishETagDxe/RedfishETagDxe.c           | 774 ++++++++++++++++++
 4 files changed, 965 insertions(+)
 create mode 100644 RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.inf
 create mode 100644 RedfishClientPkg/Include/Protocol/EdkIIRedfishETagProtocol.h
 create mode 100644 RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.h
 create mode 100644 RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.c

diff --git a/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.inf b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.inf
new file mode 100644
index 00000000000..4315b1eaa5f
--- /dev/null
+++ b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.inf
@@ -0,0 +1,45 @@
+## @file
+#
+#  (C) Copyright 2021 Hewlett Packard Enterprise Development LP<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION               = 0x0001000b
+  BASE_NAME                 = RedfishETagDxe
+  FILE_GUID                 = F7BB0BB2-9796-485F-9F00-C0EB47E9F92B
+  MODULE_TYPE               = DXE_DRIVER
+  VERSION_STRING            = 1.0
+  ENTRY_POINT               = RedfishETagDriverEntryPoint
+  UNLOAD_IMAGE              = RedfishETagDriverUnload
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  RedfishPkg/RedfishPkg.dec
+  RedfishClientPkg/RedfishClientPkg.dec
+
+[Sources]
+  RedfishETagDxe.h
+  RedfishETagDxe.c
+
+[LibraryClasses]
+  BaseLib
+  BaseMemoryLib
+  DebugLib
+  MemoryAllocationLib
+  UefiLib
+  UefiBootServicesTableLib
+  UefiRuntimeServicesTableLib
+  UefiDriverEntryPoint
+
+[Protocols]
+  gEdkIIRedfishETagProtocolGuid           ## PRODUCED ##
+
+[Guids]
+  gEfiEventExitBootServicesGuid           ## CONSUMES ## Event
+
+[Depex]
+  TRUE
diff --git a/RedfishClientPkg/Include/Protocol/EdkIIRedfishETagProtocol.h b/RedfishClientPkg/Include/Protocol/EdkIIRedfishETagProtocol.h
new file mode 100644
index 00000000000..3cbced44eb7
--- /dev/null
+++ b/RedfishClientPkg/Include/Protocol/EdkIIRedfishETagProtocol.h
@@ -0,0 +1,76 @@
+/** @file
+  This file defines the EDKII_REDFISH_FEATURE_PROTOCOL interface.
+
+  (C) Copyright 2021 Hewlett Packard Enterprise Development LP<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef EDKII_REDFISH_ETAG_PROTOCOL_H_
+#define EDKII_REDFISH_ETAG_PROTOCOL_H_
+
+typedef struct _EDKII_REDFISH_ETAG_PROTOCOL EDKII_REDFISH_ETAG_PROTOCOL;
+
+/**
+  Get ETag string by given URI
+
+  @param[in]   This                    Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+  @param[in]   Uri                     Target URI to search.
+  @param[out]  ETag                    The ETag string to corresponding URI.
+
+  @retval EFI_SUCCESS                  The ETag is found successfully.
+  @retval EFI_INVALID_PARAMETER        Invalid parameter is given.
+
+**/
+typedef
+EFI_STATUS
+(EFIAPI *EDKII_REDFISH_ETAG_PROTOCOL_GET) (
+  IN  EDKII_REDFISH_ETAG_PROTOCOL *This,
+  IN  CHAR8                       *Uri,
+  OUT CHAR8                       **ETag
+  );
+
+/**
+  Keep ETag string which maps to given Uri.
+
+  @param[in]   This                Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+  @param[in]   Uri                 The target Uri which related to ETag.
+  @param[in]   ETag                The ETag to add. If ETag is NULL, the record of correspoonding URI will be removed.
+
+  @retval EFI_SUCCESS              This handler has been stoped successfully.
+  @retval Others                   Some error happened.
+
+**/
+typedef
+EFI_STATUS
+(EFIAPI *EDKII_REDFISH_ETAG_PROTOCOL_SET) (
+  IN  EDKII_REDFISH_ETAG_PROTOCOL   *This,
+  IN  CHAR8                         *Uri,
+  IN  CHAR8                         *ETag
+  );
+
+/**
+  Refresh the ETag database and save database to variable.
+
+  @param[in]   This                Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+
+  @retval EFI_SUCCESS              This handler has been stoped successfully.
+  @retval Others                   Some error happened.
+
+**/
+typedef
+EFI_STATUS
+(EFIAPI *EDKII_REDFISH_ETAG_PROTOCOL_FLUSH) (
+  IN  EDKII_REDFISH_ETAG_PROTOCOL    *This
+  );
+
+struct _EDKII_REDFISH_ETAG_PROTOCOL {
+  EDKII_REDFISH_ETAG_PROTOCOL_GET   Get;
+  EDKII_REDFISH_ETAG_PROTOCOL_SET   Set;
+  EDKII_REDFISH_ETAG_PROTOCOL_FLUSH Flush;
+};
+
+extern EFI_GUID gEdkIIRedfishETagProtocolGuid;
+
+#endif
diff --git a/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.h b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.h
new file mode 100644
index 00000000000..c4465743133
--- /dev/null
+++ b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.h
@@ -0,0 +1,70 @@
+/** @file
+  Common header file for RedfishETagDxe driver.
+
+  (C) Copyright 2021 Hewlett Packard Enterprise Development LP<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef REDFISH_ETAG_DXE_H_
+#define REDFISH_ETAG_DXE_H_
+
+#include <Uefi.h>
+
+//
+// Libraries
+//
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiDriverEntryPoint.h>
+#include <Library/UefiLib.h>
+#include <Library/UefiRuntimeServicesTableLib.h>
+
+#include <Protocol/EdkIIRedfishETagProtocol.h>
+
+#include <Guid/VariableFormat.h>
+
+#define ETAG_VARIABLE_NAME    L"RedfishETag"
+#define IS_EMPTY_STRING(a) ((a) == NULL || (a)[0] == '\0')
+#define ETAG_DEBUG_ENABLED    0x00
+
+//
+// Definition of REDFISH_ETAG_RECORD
+//
+typedef struct {
+  LIST_ENTRY  List;
+  CHAR8       *Uri;
+  CHAR8       *ETag;
+  UINTN       Size;
+} REDFISH_ETAG_RECORD;
+
+#define REDFISH_ETAG_RECORD_FROM_LIST(a)  BASE_CR (a, REDFISH_ETAG_RECORD, List)
+
+//
+// Definition of REDFISH_ETAG_LIST
+//
+typedef struct {
+  LIST_ENTRY    Listheader;
+  UINTN         TotalSize;
+  UINTN         Count;
+} REDFISH_ETAG_LIST;
+
+//
+// Definition of REDFISH_ETAG_PRIVATE_DATA
+//
+typedef struct {
+  EFI_HANDLE                  ImageHandle;
+  REDFISH_ETAG_LIST           ETagList;
+  EDKII_REDFISH_ETAG_PROTOCOL Protocol;
+  EFI_STRING                  VariableName;
+  EFI_EVENT                   Event;
+} REDFISH_ETAG_PRIVATE_DATA;
+
+#define REDFISH_ETAG_PRIVATE_FROM_THIS(a)  BASE_CR (a, REDFISH_ETAG_PRIVATE_DATA, Protocol)
+
+#endif
diff --git a/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.c b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.c
new file mode 100644
index 00000000000..349175340d4
--- /dev/null
+++ b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.c
@@ -0,0 +1,774 @@
+/** @file
+
+  (C) Copyright 2021 Hewlett Packard Enterprise Development LP<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "RedfishETagDxe.h"
+
+REDFISH_ETAG_PRIVATE_DATA  *mRedfishETagPrivate = NULL;
+
+/**
+  Release REDFISH_ETAG_RECORD resource
+
+  @param[in]    Record    Pointer to REDFISH_ETAG_RECORD instance
+
+  @retval EFI_SUCCESS             REDFISH_ETAG_RECORD is released successfully.
+  @retval EFI_INVALID_PARAMETER   Record is NULL
+
+**/
+EFI_STATUS
+ReleaseETagRecord (
+  IN REDFISH_ETAG_RECORD *Record
+  )
+{
+  if (Record == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (Record->Uri != NULL) {
+    FreePool (Record->Uri);
+  }
+
+  if (Record->ETag != NULL) {
+    FreePool (Record->ETag);
+  }
+
+  FreePool (Record);
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Create new Etag resource.
+
+  @param[in]    Uri   The URI string matching to this ETAG.
+  @param[in]    ETag  ETAG string.
+
+  @retval REDFISH_ETAG_RECORD *   Pointer to newly created ETAG.
+  @retval NULL                    No memory available.
+
+**/
+REDFISH_ETAG_RECORD *
+NewETagRecord (
+  IN  CHAR8   *Uri,
+  IN  CHAR8   *ETag
+  )
+{
+  REDFISH_ETAG_RECORD *NewRecord;
+  UINTN               Size;
+
+  if (IS_EMPTY_STRING (Uri) || IS_EMPTY_STRING (ETag)) {
+    return NULL;
+  }
+
+  NewRecord = AllocateZeroPool (sizeof (REDFISH_ETAG_RECORD));
+  if (NewRecord == NULL) {
+    return NULL;
+  }
+
+  Size = AsciiStrSize (Uri);
+  NewRecord->Uri = AllocateCopyPool (Size, Uri);
+  if (NewRecord->Uri == NULL) {
+    goto ON_ERROR;
+  }
+
+  NewRecord->Size = Size;
+  Size = AsciiStrSize (ETag);
+  NewRecord->ETag = AllocateCopyPool (Size, ETag);
+  if (NewRecord->ETag == NULL) {
+    goto ON_ERROR;
+  }
+
+  NewRecord->Size += Size;
+  return NewRecord;
+
+ON_ERROR:
+
+  if (NewRecord != NULL) {
+    ReleaseETagRecord (NewRecord);
+  }
+
+  return NULL;
+}
+
+/**
+  Add new ETAG by given URI and ETAG string to specify List.
+
+  @param[in]    List  Target ETAG list to add.
+  @param[in]    Uri   The URI string matching to this ETAG.
+  @param[in]    ETag  ETAG string.
+
+  @retval EFI_SUCCESS   ETAG recourd is added.
+  @retval Others        Fail to add ETAG.
+
+**/
+EFI_STATUS
+AddETagRecord (
+  IN  REDFISH_ETAG_LIST *List,
+  IN  CHAR8             *Uri,
+  IN  CHAR8             *ETag
+  )
+{
+  REDFISH_ETAG_RECORD *NewRecord;
+
+  if (List == NULL || IS_EMPTY_STRING (Uri) || IS_EMPTY_STRING (ETag)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  NewRecord = NewETagRecord (Uri, ETag);
+  if (NewETagRecord == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  InsertTailList (&List->Listheader, &NewRecord->List);
+  ++List->Count;
+  List->TotalSize += NewRecord->Size;
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Delete an ETAG by given ETAG instance.
+
+  @param[in]    List    Target ETAG list to be removed.
+  @param[in]    Record  Pointer to the instance to be deleted.
+
+  @retval EFI_SUCCESS   ETAG recourd is removed.
+  @retval Others        Fail to add ETAG.
+
+**/
+EFI_STATUS
+DeleteETagRecord (
+  IN  REDFISH_ETAG_LIST   *List,
+  IN  REDFISH_ETAG_RECORD *Record
+  )
+{
+  if (List == NULL || Record == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  RemoveEntryList (&Record->List);
+  --List->Count;
+  List->TotalSize -= Record->Size;
+
+  return ReleaseETagRecord (Record);
+}
+
+/**
+  Search on given ListHeader for given URI string.
+
+  @param[in]    ListHeader  Target list to search.
+  @param[in]    Uri         Target URI to search.
+
+  @retval REDFISH_ETAG_RECORD   Target ETAG is found.
+  @retval NULL                  No ETAG with given URI is found.
+
+**/
+REDFISH_ETAG_RECORD *
+FindETagRecord (
+  IN  LIST_ENTRY  *ListHeader,
+  IN  CHAR8       *Uri
+  )
+{
+  LIST_ENTRY          *List;
+  REDFISH_ETAG_RECORD *Record;
+
+  if (IsListEmpty (ListHeader)) {
+    return NULL;
+  }
+
+  Record = NULL;
+  List = GetFirstNode (ListHeader);
+  while (!IsNull (ListHeader, List)) {
+    Record = REDFISH_ETAG_RECORD_FROM_LIST (List);
+
+    if (AsciiStrCmp (Record->Uri, Uri) == 0) {
+      return  Record;
+    }
+
+    List = GetNextNode (ListHeader, List);
+  }
+
+  return NULL;
+}
+
+#if ETAG_DEBUG_ENABLED
+/**
+  Debug output the ETAG list.
+
+  @param[in]    ETagList  Target list to dump
+  @param[in]    Msg       Debug message string.
+
+  @retval EFI_SUCCESS             Debug dump finished.
+  @retval EFI_INVALID_PARAMETER   ETagList is NULL.
+
+**/
+EFI_STATUS
+DumpETagList (
+  IN  REDFISH_ETAG_LIST   *ETagList,
+  IN  EFI_STRING          Msg
+  )
+{
+  LIST_ENTRY          *List;
+  REDFISH_ETAG_RECORD *Record;
+
+  if (ETagList == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (!IS_EMPTY_STRING (Msg)) {
+    DEBUG ((DEBUG_ERROR, "%s\n", Msg));
+  }
+
+  if (IsListEmpty (&ETagList->Listheader)) {
+    DEBUG ((DEBUG_INFO, "ETag list is empty\n"));
+    return EFI_NOT_FOUND;
+  }
+
+  DEBUG ((DEBUG_INFO, "Count: %d Total Size: %d\n", ETagList->Count, ETagList->TotalSize));
+  Record = NULL;
+  List = GetFirstNode (&ETagList->Listheader);
+  while (!IsNull (&ETagList->Listheader, List)) {
+    Record = REDFISH_ETAG_RECORD_FROM_LIST (List);
+
+    DEBUG ((DEBUG_INFO, "ETag: %a Uri: %a Size: %d\n", Record->ETag, Record->Uri, Record->Size));
+
+    List = GetNextNode (&ETagList->Listheader, List);
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Debug output raw data buffer.
+
+  @param[in]    Buffer      Debug output data buffer.
+  @param[in]    BufferSize  The size of Buffer in byte.
+
+  @retval EFI_SUCCESS             Debug dump finished.
+  @retval EFI_INVALID_PARAMETER   Buffer is NULL.
+
+**/
+EFI_STATUS
+DumpRawBuffer (
+  IN  CHAR8    *Buffer,
+  IN  UINTN     BufferSize
+  )
+{
+  UINTN  Index;
+
+  if (Buffer == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Index = 0;
+
+  DEBUG ((DEBUG_ERROR, "Buffer size: %d\n", BufferSize));
+  while (Buffer[Index] != '\0') {
+    DEBUG ((DEBUG_ERROR, "(%d) %c ", (Index + 1), Buffer[Index]));
+
+    ++Index;
+  }
+  DEBUG ((DEBUG_ERROR, "\n"));
+
+  return EFI_SUCCESS;
+}
+#endif
+
+/**
+  Release all ETag from list.
+
+  @param[in]    ETagList    The list to be released.
+
+  @retval EFI_SUCCESS             All etag is released.
+  @retval EFI_INVALID_PARAMETER   ETagList is NULL.
+
+**/
+EFI_STATUS
+ReleaseETagList (
+  IN  REDFISH_ETAG_LIST   *ETagList
+  )
+{
+  LIST_ENTRY          *List;
+  LIST_ENTRY          *Next;
+  REDFISH_ETAG_RECORD *Record;
+
+  if (ETagList == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (IsListEmpty (&ETagList->Listheader)) {
+    return EFI_SUCCESS;
+  }
+
+  Record = NULL;
+  Next = NULL;
+  List = GetFirstNode (&ETagList->Listheader);
+  while (!IsNull (&ETagList->Listheader, List)) {
+    Record = REDFISH_ETAG_RECORD_FROM_LIST (List);
+    Next = GetNextNode (&ETagList->Listheader, List);
+
+    DeleteETagRecord (ETagList, Record);
+
+    List = Next;
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Save etag in list to UEFI variable.
+
+  @param[in]    ETagList      The list to be saved.
+  @param[in]    VariableName  The UEFI variable name.
+
+  @retval EFI_SUCCESS             All etag is saved.
+  @retval EFI_INVALID_PARAMETER   VariableName or ETagList is NULL.
+
+**/
+EFI_STATUS
+SaveETagList (
+  IN  REDFISH_ETAG_LIST   *ETagList,
+  IN  EFI_STRING          VariableName
+  )
+{
+  LIST_ENTRY          *List;
+  REDFISH_ETAG_RECORD *Record;
+  CHAR8               *VarData;
+  VOID                *Data;
+  CHAR8               *Seeker;
+  UINTN               VarSize;
+  UINTN               StrSize;
+  EFI_STATUS          Status;
+
+  if (ETagList == NULL || IS_EMPTY_STRING (VariableName)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (IsListEmpty (&ETagList->Listheader)) {
+    return EFI_SUCCESS;
+  }
+
+  //
+  // Caculate the total size we need to keep ETag list.
+  //
+  VarSize = ETagList->TotalSize + 1; // terminator character
+  VarData = AllocateZeroPool (VarSize);
+  if (VarData == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  Seeker = VarData;
+  Record = NULL;
+  List = GetFirstNode (&ETagList->Listheader);
+  while (!IsNull (&ETagList->Listheader, List)) {
+    Record = REDFISH_ETAG_RECORD_FROM_LIST (List);
+
+    StrSize = AsciiStrSize (Record->Uri);
+    CopyMem (Seeker, Record->Uri, StrSize);
+
+    Seeker += (StrSize - 1);
+    *Seeker = '|';
+    ++Seeker;
+
+    StrSize = AsciiStrSize (Record->ETag);
+    CopyMem (Seeker, Record->ETag, StrSize);
+
+    Seeker += (StrSize - 1);
+    *Seeker = '\n';
+
+    ++Seeker;
+
+    List = GetNextNode (&ETagList->Listheader, List);;
+  }
+
+  *Seeker = '\0';
+
+#if ETAG_DEBUG_ENABLED
+  DumpRawBuffer (VarData, VarSize);
+#endif
+
+  ASSERT (((UINTN)Seeker - (UINTN)VarData + 1) == VarSize);
+
+  //
+  // Check if variable exists already. If yes, remove it first.
+  //
+  Status = GetVariable2 (
+             VariableName,
+             &gEfiCallerIdGuid,
+             (VOID *)&Data,
+             NULL
+             );
+  if (!EFI_ERROR (Status)) {
+    FreePool (Data);
+    gRT->SetVariable (VariableName, &gEfiCallerIdGuid, VARIABLE_ATTRIBUTE_NV_BS, 0, NULL);
+  }
+
+
+  return gRT->SetVariable (VariableName, &gEfiCallerIdGuid, VARIABLE_ATTRIBUTE_NV_BS, VarSize, (VOID *)VarData);
+}
+
+/**
+  Read etag from UEFI variable if it exists.
+
+  @param[in]    ETagList      The list to be loaded.
+  @param[in]    VariableName  The UEFI variable name.
+
+  @retval EFI_SUCCESS             All etag is read successfully.
+  @retval EFI_INVALID_PARAMETER   VariableName or ETagList is NULL.
+  @retval EFI_NOT_FOUND           No etag is found on UEFI variable.
+
+**/
+EFI_STATUS
+InitialETagList (
+  IN  REDFISH_ETAG_LIST   *ETagList,
+  IN  EFI_STRING          VariableName
+  )
+{
+  CHAR8     *VarData;
+  CHAR8     *UriPointer;
+  CHAR8     *ETagPointer;
+  CHAR8     *Seeker;
+  UINTN      VariableSize;
+  EFI_STATUS Status;
+
+  if (ETagList == NULL || IS_EMPTY_STRING (VariableName)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  //
+  // Check if variable exists already.
+  //
+  Status = GetVariable2 (
+             VariableName,
+             &gEfiCallerIdGuid,
+             (VOID *)&VarData,
+             &VariableSize
+             );
+  if (EFI_ERROR (Status)) {
+    return EFI_NOT_FOUND;
+  }
+
+  Seeker = VarData;
+  UriPointer = VarData;
+  ETagPointer = VarData;
+  while (*Seeker != '\0') {
+
+    //
+    // Find URI
+    //
+    Seeker = AsciiStrStr (UriPointer, "|");
+    if (Seeker == NULL) {
+      DEBUG ((DEBUG_ERROR, "%a, data corrupted\n", __FUNCTION__));
+      Status = EFI_DEVICE_ERROR;
+      goto ON_ERROR;
+    }
+
+    *Seeker = '\0';
+    ETagPointer = ++Seeker;
+
+    //
+    // Find ETAG
+    //
+    Seeker = AsciiStrStr (ETagPointer, "\n");
+    if (Seeker == NULL) {
+      DEBUG ((DEBUG_ERROR, "%a, data corrupted\n", __FUNCTION__));
+      Status = EFI_DEVICE_ERROR;
+      goto ON_ERROR;
+    }
+
+    *Seeker = '\0';
+
+    AddETagRecord (ETagList, UriPointer, ETagPointer);
+
+    UriPointer = ++Seeker;
+  }
+
+#if ETAG_DEBUG_ENABLED
+  DumpETagList (ETagList, L"Initial ETag List from Variable");
+#endif
+
+  Status = EFI_SUCCESS;
+
+ON_ERROR:
+
+  FreePool (VarData);
+
+  return Status;
+}
+
+/**
+  Get ETag string by given URI
+
+  @param[in]   This                    Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+  @param[in]   Uri                     Target URI to search.
+  @param[out]  ETag                    The ETag string to corresponding URI.
+
+  @retval EFI_SUCCESS                  The ETag is found successfully.
+  @retval EFI_INVALID_PARAMETER        Invalid parameter is given.
+
+**/
+EFI_STATUS
+RedfishETagGet (
+  IN  EDKII_REDFISH_ETAG_PROTOCOL *This,
+  IN  CHAR8                     *Uri,
+  OUT CHAR8                     **ETag
+  )
+{
+  REDFISH_ETAG_RECORD       *Target;
+  REDFISH_ETAG_PRIVATE_DATA *Private;
+
+  if (This == NULL || IS_EMPTY_STRING (Uri) || ETag == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Private = REDFISH_ETAG_PRIVATE_FROM_THIS (This);
+
+  *ETag = NULL;
+
+  Target = FindETagRecord (&Private->ETagList.Listheader, Uri);
+  if (Target == NULL) {
+    return EFI_NOT_FOUND;
+  }
+
+  *ETag = AllocateCopyPool (AsciiStrSize (Target->ETag), Target->ETag);
+
+  return EFI_SUCCESS;
+}
+
+
+/**
+  Keep ETag string which maps to given Uri.
+
+  @param[in]   This                Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+  @param[in]   Uri                 The target Uri which related to ETag.
+  @param[in]   ETag                The ETag to add. If ETag is NULL, the record of correspoonding URI will be removed.
+
+  @retval EFI_SUCCESS              This handler has been stoped successfully.
+  @retval Others                   Some error happened.
+
+**/
+EFI_STATUS
+RedfishETagSet (
+  IN  EDKII_REDFISH_ETAG_PROTOCOL  *This,
+  IN  CHAR8                        *Uri,
+  IN  CHAR8                        *ETag  OPTIONAL
+  )
+{
+  REDFISH_ETAG_RECORD       *Target;
+  REDFISH_ETAG_PRIVATE_DATA *Private;
+  EFI_STATUS                Status;
+
+  if (This == NULL || IS_EMPTY_STRING (Uri)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Private = REDFISH_ETAG_PRIVATE_FROM_THIS (This);
+
+  Status = EFI_NOT_FOUND;
+  Target = FindETagRecord (&Private->ETagList.Listheader, Uri);
+  if (Target != NULL) {
+    //
+    // Remove old one and create new one.
+    //
+    Status = DeleteETagRecord (&Private->ETagList, Target);
+  }
+
+  //
+  // When ETag is NULL, it means that we want to remov this record.
+  //
+  if (ETag == NULL) {
+    return Status;
+  }
+
+  return AddETagRecord (&Private->ETagList, Uri, ETag);
+}
+
+/**
+  Refresh the ETag database and save database to variable.
+
+  @param[in]   This                Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+
+  @retval EFI_SUCCESS              This handler has been stoped successfully.
+  @retval Others                   Some error happened.
+
+**/
+EFI_STATUS
+RedfishETagFlush (
+  IN  EDKII_REDFISH_ETAG_PROTOCOL    *This
+  )
+{
+  REDFISH_ETAG_PRIVATE_DATA *Private;
+  EFI_STATUS                Status;
+
+  if (This == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Private = REDFISH_ETAG_PRIVATE_FROM_THIS (This);
+
+  Status = SaveETagList (&Private->ETagList, Private->VariableName);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "%a, save ETag list to variable: %s failed: %r\n", __FUNCTION__, Private->VariableName, Status));
+  }
+
+  return Status;
+}
+
+/**
+  Callback function executed when the ExitBootService event group is signaled.
+
+  @param[in]   Event    Event whose notification function is being invoked.
+  @param[out]  Context  Pointer to the Context buffer
+
+**/
+VOID
+EFIAPI
+RedfishETagOnExitBootService (
+  IN  EFI_EVENT  Event,
+  OUT VOID       *Context
+  )
+{
+  //
+  // Memory is about to be released. Keep list into variable.
+  //
+  RedfishETagFlush (&mRedfishETagPrivate->Protocol);
+}
+
+/**
+  Unloads an image.
+
+  @param[in]  ImageHandle           Handle that identifies the image to be unloaded.
+
+  @retval EFI_SUCCESS           The image has been unloaded.
+  @retval EFI_INVALID_PARAMETER ImageHandle is not a valid image handle.
+
+**/
+EFI_STATUS
+EFIAPI
+RedfishETagDriverUnload (
+  IN EFI_HANDLE  ImageHandle
+  )
+{
+  EFI_STATUS  Status;
+
+  if (mRedfishETagPrivate != NULL) {
+
+    Status = gBS->UninstallProtocolInterface (
+                    mRedfishETagPrivate->ImageHandle,
+                    &gEdkIIRedfishETagProtocolGuid,
+                    (VOID*)&mRedfishETagPrivate->Protocol
+                    );
+    if (EFI_ERROR (Status)) {
+      DEBUG ((DEBUG_ERROR, "%a, can not uninstall gEdkIIRedfishETagProtocolGuid: %r\n", __FUNCTION__, Status));
+      ASSERT (FALSE);
+    }
+
+    ReleaseETagList (&mRedfishETagPrivate->ETagList);
+
+    if (mRedfishETagPrivate->VariableName != NULL) {
+      FreePool (mRedfishETagPrivate->VariableName);
+    }
+
+    if (mRedfishETagPrivate->Event != NULL) {
+      gBS->CloseEvent (mRedfishETagPrivate->Event);
+    }
+
+    FreePool (mRedfishETagPrivate);
+    mRedfishETagPrivate = NULL;
+  }
+
+
+  return EFI_SUCCESS;
+}
+
+//
+// EDKII_REDFISH_ETAG_PROTOCOL.
+//
+EDKII_REDFISH_ETAG_PROTOCOL mRedfishETagProtocol = {
+  RedfishETagGet,
+  RedfishETagSet,
+  RedfishETagFlush
+};
+
+/**
+  This is the declaration of an EFI image entry point. This entry point is
+  the same for UEFI Applications, UEFI OS Loaders, and UEFI Drivers including
+  both device drivers and bus drivers.
+
+  @param[in]  ImageHandle       The firmware allocated handle for the UEFI image.
+  @param[in]  SystemTable       A pointer to the EFI System Table.
+
+  @retval EFI_SUCCESS           The operation completed successfully.
+  @retval Others                An unexpected error occurred.
+**/
+EFI_STATUS
+EFIAPI
+RedfishETagDriverEntryPoint (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  EFI_STATUS    Status;
+
+  mRedfishETagPrivate = AllocateZeroPool (sizeof (REDFISH_ETAG_PRIVATE_DATA));
+  if (mRedfishETagPrivate == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  InitializeListHead (&mRedfishETagPrivate->ETagList.Listheader);
+  mRedfishETagPrivate->VariableName = AllocateCopyPool (StrSize (ETAG_VARIABLE_NAME), ETAG_VARIABLE_NAME);
+  if (mRedfishETagPrivate->VariableName == NULL) {
+    goto ON_ERROR;
+  }
+
+  mRedfishETagPrivate->ImageHandle = ImageHandle;
+  CopyMem (&mRedfishETagPrivate->Protocol, &mRedfishETagProtocol, sizeof (EDKII_REDFISH_ETAG_PROTOCOL));
+
+  Status = gBS->InstallProtocolInterface (
+                  &ImageHandle,
+                  &gEdkIIRedfishETagProtocolGuid,
+                  EFI_NATIVE_INTERFACE,
+                  (VOID*)&mRedfishETagPrivate->Protocol
+                  );
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "%a, can not install gEdkIIRedfishETagProtocolGuid: %r\n", __FUNCTION__, Status));
+    ASSERT (FALSE);
+    goto ON_ERROR;
+  }
+
+  //
+  // Create Exit Boot Service event.
+  //
+  Status = gBS->CreateEventEx (
+                  EVT_NOTIFY_SIGNAL,
+                  TPL_CALLBACK,
+                  RedfishETagOnExitBootService,
+                  NULL,
+                  &gEfiEventExitBootServicesGuid,
+                  &mRedfishETagPrivate->Event
+                  );
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "%a: Fail to register Exit Boot Service event.", __FUNCTION__));
+    goto ON_ERROR;
+  }
+
+  //
+  // Read existing record from variable.
+  //
+  Status = InitialETagList (&mRedfishETagPrivate->ETagList, mRedfishETagPrivate->VariableName);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_INFO, "%a, Initial ETag List: %r\n", __FUNCTION__, Status));
+  }
+
+  return EFI_SUCCESS;
+
+ON_ERROR:
+
+  RedfishETagDriverUnload (ImageHandle);
+
+  return Status;
+}
--
2.21.0.windows.1


Abner Chang
 

Reviewed-by: Abner Chang <abner.chang@...>




From: Wang, Nickle (HPS SW) <nickle.wang@...>
Sent: Monday, October 25, 2021 4:20 PM
To: Chang, Abner (HPS SW/FW Technologist) <abner.chang@...>; devel@edk2.groups.io <devel@edk2.groups.io>
Cc: Liming Gao <gaoliming@...>
Subject: Re: [PATCH 1/2] staging/RedfishClientPkg: Add EDKII ETag driver
 
Reviewed-by: Nickle Wang <nickle.wang@...>

Thanks,
Nickle

From: Chang, Abner (HPS SW/FW Technologist) <abner.chang@...>
Sent: Monday, October 25, 2021 15:41
To: devel@edk2.groups.io <devel@edk2.groups.io>
Cc: Wang, Nickle (HPS SW) <nickle.wang@...>; Liming Gao <gaoliming@...>
Subject: [PATCH 1/2] staging/RedfishClientPkg: Add EDKII ETag driver
 
Implement EDKII ETag protocol to manipulate ETag of
HTTP content.

Signed-off-by: Nickle Wang <nickle.wang@...>
Cc: Abner Chang <abner.chang@...>
Cc: Liming Gao <gaoliming@...>
---
 .../RedfishETagDxe/RedfishETagDxe.inf         |  45 +
 .../Protocol/EdkIIRedfishETagProtocol.h       |  76 ++
 .../RedfishETagDxe/RedfishETagDxe.h           |  70 ++
 .../RedfishETagDxe/RedfishETagDxe.c           | 774 ++++++++++++++++++
 4 files changed, 965 insertions(+)
 create mode 100644 RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.inf
 create mode 100644 RedfishClientPkg/Include/Protocol/EdkIIRedfishETagProtocol.h
 create mode 100644 RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.h
 create mode 100644 RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.c

diff --git a/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.inf b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.inf
new file mode 100644
index 00000000000..4315b1eaa5f
--- /dev/null
+++ b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.inf
@@ -0,0 +1,45 @@
+## @file
+#
+#  (C) Copyright 2021 Hewlett Packard Enterprise Development LP<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION               = 0x0001000b
+  BASE_NAME                 = RedfishETagDxe
+  FILE_GUID                 = F7BB0BB2-9796-485F-9F00-C0EB47E9F92B
+  MODULE_TYPE               = DXE_DRIVER
+  VERSION_STRING            = 1.0
+  ENTRY_POINT               = RedfishETagDriverEntryPoint
+  UNLOAD_IMAGE              = RedfishETagDriverUnload
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  RedfishPkg/RedfishPkg.dec
+  RedfishClientPkg/RedfishClientPkg.dec
+
+[Sources]
+  RedfishETagDxe.h
+  RedfishETagDxe.c
+
+[LibraryClasses]
+  BaseLib
+  BaseMemoryLib
+  DebugLib
+  MemoryAllocationLib
+  UefiLib
+  UefiBootServicesTableLib
+  UefiRuntimeServicesTableLib
+  UefiDriverEntryPoint
+
+[Protocols]
+  gEdkIIRedfishETagProtocolGuid           ## PRODUCED ##
+
+[Guids]
+  gEfiEventExitBootServicesGuid           ## CONSUMES ## Event
+
+[Depex]
+  TRUE
diff --git a/RedfishClientPkg/Include/Protocol/EdkIIRedfishETagProtocol.h b/RedfishClientPkg/Include/Protocol/EdkIIRedfishETagProtocol.h
new file mode 100644
index 00000000000..3cbced44eb7
--- /dev/null
+++ b/RedfishClientPkg/Include/Protocol/EdkIIRedfishETagProtocol.h
@@ -0,0 +1,76 @@
+/** @file
+  This file defines the EDKII_REDFISH_FEATURE_PROTOCOL interface.
+
+  (C) Copyright 2021 Hewlett Packard Enterprise Development LP<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef EDKII_REDFISH_ETAG_PROTOCOL_H_
+#define EDKII_REDFISH_ETAG_PROTOCOL_H_
+
+typedef struct _EDKII_REDFISH_ETAG_PROTOCOL EDKII_REDFISH_ETAG_PROTOCOL;
+
+/**
+  Get ETag string by given URI
+
+  @param[in]   This                    Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+  @param[in]   Uri                     Target URI to search.
+  @param[out]  ETag                    The ETag string to corresponding URI.
+
+  @retval EFI_SUCCESS                  The ETag is found successfully.
+  @retval EFI_INVALID_PARAMETER        Invalid parameter is given.
+
+**/
+typedef
+EFI_STATUS
+(EFIAPI *EDKII_REDFISH_ETAG_PROTOCOL_GET) (
+  IN  EDKII_REDFISH_ETAG_PROTOCOL *This,
+  IN  CHAR8                       *Uri,
+  OUT CHAR8                       **ETag
+  );
+
+/**
+  Keep ETag string which maps to given Uri.
+
+  @param[in]   This                Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+  @param[in]   Uri                 The target Uri which related to ETag.
+  @param[in]   ETag                The ETag to add. If ETag is NULL, the record of correspoonding URI will be removed.
+
+  @retval EFI_SUCCESS              This handler has been stoped successfully.
+  @retval Others                   Some error happened.
+
+**/
+typedef
+EFI_STATUS
+(EFIAPI *EDKII_REDFISH_ETAG_PROTOCOL_SET) (
+  IN  EDKII_REDFISH_ETAG_PROTOCOL   *This,
+  IN  CHAR8                         *Uri,
+  IN  CHAR8                         *ETag
+  );
+
+/**
+  Refresh the ETag database and save database to variable.
+
+  @param[in]   This                Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+
+  @retval EFI_SUCCESS              This handler has been stoped successfully.
+  @retval Others                   Some error happened.
+
+**/
+typedef
+EFI_STATUS
+(EFIAPI *EDKII_REDFISH_ETAG_PROTOCOL_FLUSH) (
+  IN  EDKII_REDFISH_ETAG_PROTOCOL    *This
+  );
+
+struct _EDKII_REDFISH_ETAG_PROTOCOL {
+  EDKII_REDFISH_ETAG_PROTOCOL_GET   Get;
+  EDKII_REDFISH_ETAG_PROTOCOL_SET   Set;
+  EDKII_REDFISH_ETAG_PROTOCOL_FLUSH Flush;
+};
+
+extern EFI_GUID gEdkIIRedfishETagProtocolGuid;
+
+#endif
diff --git a/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.h b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.h
new file mode 100644
index 00000000000..c4465743133
--- /dev/null
+++ b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.h
@@ -0,0 +1,70 @@
+/** @file
+  Common header file for RedfishETagDxe driver.
+
+  (C) Copyright 2021 Hewlett Packard Enterprise Development LP<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef REDFISH_ETAG_DXE_H_
+#define REDFISH_ETAG_DXE_H_
+
+#include <Uefi.h>
+
+//
+// Libraries
+//
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiDriverEntryPoint.h>
+#include <Library/UefiLib.h>
+#include <Library/UefiRuntimeServicesTableLib.h>
+
+#include <Protocol/EdkIIRedfishETagProtocol.h>
+
+#include <Guid/VariableFormat.h>
+
+#define ETAG_VARIABLE_NAME    L"RedfishETag"
+#define IS_EMPTY_STRING(a) ((a) == NULL || (a)[0] == '\0')
+#define ETAG_DEBUG_ENABLED    0x00
+
+//
+// Definition of REDFISH_ETAG_RECORD
+//
+typedef struct {
+  LIST_ENTRY  List;
+  CHAR8       *Uri;
+  CHAR8       *ETag;
+  UINTN       Size;
+} REDFISH_ETAG_RECORD;
+
+#define REDFISH_ETAG_RECORD_FROM_LIST(a)  BASE_CR (a, REDFISH_ETAG_RECORD, List)
+
+//
+// Definition of REDFISH_ETAG_LIST
+//
+typedef struct {
+  LIST_ENTRY    Listheader;
+  UINTN         TotalSize;
+  UINTN         Count;
+} REDFISH_ETAG_LIST;
+
+//
+// Definition of REDFISH_ETAG_PRIVATE_DATA
+//
+typedef struct {
+  EFI_HANDLE                  ImageHandle;
+  REDFISH_ETAG_LIST           ETagList;
+  EDKII_REDFISH_ETAG_PROTOCOL Protocol;
+  EFI_STRING                  VariableName;
+  EFI_EVENT                   Event;
+} REDFISH_ETAG_PRIVATE_DATA;
+
+#define REDFISH_ETAG_PRIVATE_FROM_THIS(a)  BASE_CR (a, REDFISH_ETAG_PRIVATE_DATA, Protocol)
+
+#endif
diff --git a/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.c b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.c
new file mode 100644
index 00000000000..349175340d4
--- /dev/null
+++ b/RedfishClientPkg/RedfishETagDxe/RedfishETagDxe.c
@@ -0,0 +1,774 @@
+/** @file
+
+  (C) Copyright 2021 Hewlett Packard Enterprise Development LP<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "RedfishETagDxe.h"
+
+REDFISH_ETAG_PRIVATE_DATA  *mRedfishETagPrivate = NULL;
+
+/**
+  Release REDFISH_ETAG_RECORD resource
+
+  @param[in]    Record    Pointer to REDFISH_ETAG_RECORD instance
+
+  @retval EFI_SUCCESS             REDFISH_ETAG_RECORD is released successfully.
+  @retval EFI_INVALID_PARAMETER   Record is NULL
+
+**/
+EFI_STATUS
+ReleaseETagRecord (
+  IN REDFISH_ETAG_RECORD *Record
+  )
+{
+  if (Record == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (Record->Uri != NULL) {
+    FreePool (Record->Uri);
+  }
+
+  if (Record->ETag != NULL) {
+    FreePool (Record->ETag);
+  }
+
+  FreePool (Record);
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Create new Etag resource.
+
+  @param[in]    Uri   The URI string matching to this ETAG.
+  @param[in]    ETag  ETAG string.
+
+  @retval REDFISH_ETAG_RECORD *   Pointer to newly created ETAG.
+  @retval NULL                    No memory available.
+
+**/
+REDFISH_ETAG_RECORD *
+NewETagRecord (
+  IN  CHAR8   *Uri,
+  IN  CHAR8   *ETag
+  )
+{
+  REDFISH_ETAG_RECORD *NewRecord;
+  UINTN               Size;
+
+  if (IS_EMPTY_STRING (Uri) || IS_EMPTY_STRING (ETag)) {
+    return NULL;
+  }
+
+  NewRecord = AllocateZeroPool (sizeof (REDFISH_ETAG_RECORD));
+  if (NewRecord == NULL) {
+    return NULL;
+  }
+
+  Size = AsciiStrSize (Uri);
+  NewRecord->Uri = AllocateCopyPool (Size, Uri);
+  if (NewRecord->Uri == NULL) {
+    goto ON_ERROR;
+  }
+
+  NewRecord->Size = Size;
+  Size = AsciiStrSize (ETag);
+  NewRecord->ETag = AllocateCopyPool (Size, ETag);
+  if (NewRecord->ETag == NULL) {
+    goto ON_ERROR;
+  }
+
+  NewRecord->Size += Size;
+  return NewRecord;
+
+ON_ERROR:
+
+  if (NewRecord != NULL) {
+    ReleaseETagRecord (NewRecord);
+  }
+
+  return NULL;
+}
+
+/**
+  Add new ETAG by given URI and ETAG string to specify List.
+
+  @param[in]    List  Target ETAG list to add.
+  @param[in]    Uri   The URI string matching to this ETAG.
+  @param[in]    ETag  ETAG string.
+
+  @retval EFI_SUCCESS   ETAG recourd is added.
+  @retval Others        Fail to add ETAG.
+
+**/
+EFI_STATUS
+AddETagRecord (
+  IN  REDFISH_ETAG_LIST *List,
+  IN  CHAR8             *Uri,
+  IN  CHAR8             *ETag
+  )
+{
+  REDFISH_ETAG_RECORD *NewRecord;
+
+  if (List == NULL || IS_EMPTY_STRING (Uri) || IS_EMPTY_STRING (ETag)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  NewRecord = NewETagRecord (Uri, ETag);
+  if (NewETagRecord == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  InsertTailList (&List->Listheader, &NewRecord->List);
+  ++List->Count;
+  List->TotalSize += NewRecord->Size;
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Delete an ETAG by given ETAG instance.
+
+  @param[in]    List    Target ETAG list to be removed.
+  @param[in]    Record  Pointer to the instance to be deleted.
+
+  @retval EFI_SUCCESS   ETAG recourd is removed.
+  @retval Others        Fail to add ETAG.
+
+**/
+EFI_STATUS
+DeleteETagRecord (
+  IN  REDFISH_ETAG_LIST   *List,
+  IN  REDFISH_ETAG_RECORD *Record
+  )
+{
+  if (List == NULL || Record == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  RemoveEntryList (&Record->List);
+  --List->Count;
+  List->TotalSize -= Record->Size;
+
+  return ReleaseETagRecord (Record);
+}
+
+/**
+  Search on given ListHeader for given URI string.
+
+  @param[in]    ListHeader  Target list to search.
+  @param[in]    Uri         Target URI to search.
+
+  @retval REDFISH_ETAG_RECORD   Target ETAG is found.
+  @retval NULL                  No ETAG with given URI is found.
+
+**/
+REDFISH_ETAG_RECORD *
+FindETagRecord (
+  IN  LIST_ENTRY  *ListHeader,
+  IN  CHAR8       *Uri
+  )
+{
+  LIST_ENTRY          *List;
+  REDFISH_ETAG_RECORD *Record;
+
+  if (IsListEmpty (ListHeader)) {
+    return NULL;
+  }
+
+  Record = NULL;
+  List = GetFirstNode (ListHeader);
+  while (!IsNull (ListHeader, List)) {
+    Record = REDFISH_ETAG_RECORD_FROM_LIST (List);
+
+    if (AsciiStrCmp (Record->Uri, Uri) == 0) {
+      return  Record;
+    }
+
+    List = GetNextNode (ListHeader, List);
+  }
+
+  return NULL;
+}
+
+#if ETAG_DEBUG_ENABLED
+/**
+  Debug output the ETAG list.
+
+  @param[in]    ETagList  Target list to dump
+  @param[in]    Msg       Debug message string.
+
+  @retval EFI_SUCCESS             Debug dump finished.
+  @retval EFI_INVALID_PARAMETER   ETagList is NULL.
+
+**/
+EFI_STATUS
+DumpETagList (
+  IN  REDFISH_ETAG_LIST   *ETagList,
+  IN  EFI_STRING          Msg
+  )
+{
+  LIST_ENTRY          *List;
+  REDFISH_ETAG_RECORD *Record;
+
+  if (ETagList == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (!IS_EMPTY_STRING (Msg)) {
+    DEBUG ((DEBUG_ERROR, "%s\n", Msg));
+  }
+
+  if (IsListEmpty (&ETagList->Listheader)) {
+    DEBUG ((DEBUG_INFO, "ETag list is empty\n"));
+    return EFI_NOT_FOUND;
+  }
+
+  DEBUG ((DEBUG_INFO, "Count: %d Total Size: %d\n", ETagList->Count, ETagList->TotalSize));
+  Record = NULL;
+  List = GetFirstNode (&ETagList->Listheader);
+  while (!IsNull (&ETagList->Listheader, List)) {
+    Record = REDFISH_ETAG_RECORD_FROM_LIST (List);
+
+    DEBUG ((DEBUG_INFO, "ETag: %a Uri: %a Size: %d\n", Record->ETag, Record->Uri, Record->Size));
+
+    List = GetNextNode (&ETagList->Listheader, List);
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Debug output raw data buffer.
+
+  @param[in]    Buffer      Debug output data buffer.
+  @param[in]    BufferSize  The size of Buffer in byte.
+
+  @retval EFI_SUCCESS             Debug dump finished.
+  @retval EFI_INVALID_PARAMETER   Buffer is NULL.
+
+**/
+EFI_STATUS
+DumpRawBuffer (
+  IN  CHAR8    *Buffer,
+  IN  UINTN     BufferSize
+  )
+{
+  UINTN  Index;
+
+  if (Buffer == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Index = 0;
+
+  DEBUG ((DEBUG_ERROR, "Buffer size: %d\n", BufferSize));
+  while (Buffer[Index] != '\0') {
+    DEBUG ((DEBUG_ERROR, "(%d) %c ", (Index + 1), Buffer[Index]));
+
+    ++Index;
+  }
+  DEBUG ((DEBUG_ERROR, "\n"));
+
+  return EFI_SUCCESS;
+}
+#endif
+
+/**
+  Release all ETag from list.
+
+  @param[in]    ETagList    The list to be released.
+
+  @retval EFI_SUCCESS             All etag is released.
+  @retval EFI_INVALID_PARAMETER   ETagList is NULL.
+
+**/
+EFI_STATUS
+ReleaseETagList (
+  IN  REDFISH_ETAG_LIST   *ETagList
+  )
+{
+  LIST_ENTRY          *List;
+  LIST_ENTRY          *Next;
+  REDFISH_ETAG_RECORD *Record;
+
+  if (ETagList == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (IsListEmpty (&ETagList->Listheader)) {
+    return EFI_SUCCESS;
+  }
+
+  Record = NULL;
+  Next = NULL;
+  List = GetFirstNode (&ETagList->Listheader);
+  while (!IsNull (&ETagList->Listheader, List)) {
+    Record = REDFISH_ETAG_RECORD_FROM_LIST (List);
+    Next = GetNextNode (&ETagList->Listheader, List);
+
+    DeleteETagRecord (ETagList, Record);
+
+    List = Next;
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Save etag in list to UEFI variable.
+
+  @param[in]    ETagList      The list to be saved.
+  @param[in]    VariableName  The UEFI variable name.
+
+  @retval EFI_SUCCESS             All etag is saved.
+  @retval EFI_INVALID_PARAMETER   VariableName or ETagList is NULL.
+
+**/
+EFI_STATUS
+SaveETagList (
+  IN  REDFISH_ETAG_LIST   *ETagList,
+  IN  EFI_STRING          VariableName
+  )
+{
+  LIST_ENTRY          *List;
+  REDFISH_ETAG_RECORD *Record;
+  CHAR8               *VarData;
+  VOID                *Data;
+  CHAR8               *Seeker;
+  UINTN               VarSize;
+  UINTN               StrSize;
+  EFI_STATUS          Status;
+
+  if (ETagList == NULL || IS_EMPTY_STRING (VariableName)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (IsListEmpty (&ETagList->Listheader)) {
+    return EFI_SUCCESS;
+  }
+
+  //
+  // Caculate the total size we need to keep ETag list.
+  //
+  VarSize = ETagList->TotalSize + 1; // terminator character
+  VarData = AllocateZeroPool (VarSize);
+  if (VarData == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  Seeker = VarData;
+  Record = NULL;
+  List = GetFirstNode (&ETagList->Listheader);
+  while (!IsNull (&ETagList->Listheader, List)) {
+    Record = REDFISH_ETAG_RECORD_FROM_LIST (List);
+
+    StrSize = AsciiStrSize (Record->Uri);
+    CopyMem (Seeker, Record->Uri, StrSize);
+
+    Seeker += (StrSize - 1);
+    *Seeker = '|';
+    ++Seeker;
+
+    StrSize = AsciiStrSize (Record->ETag);
+    CopyMem (Seeker, Record->ETag, StrSize);
+
+    Seeker += (StrSize - 1);
+    *Seeker = '\n';
+
+    ++Seeker;
+
+    List = GetNextNode (&ETagList->Listheader, List);;
+  }
+
+  *Seeker = '\0';
+
+#if ETAG_DEBUG_ENABLED
+  DumpRawBuffer (VarData, VarSize);
+#endif
+
+  ASSERT (((UINTN)Seeker - (UINTN)VarData + 1) == VarSize);
+
+  //
+  // Check if variable exists already. If yes, remove it first.
+  //
+  Status = GetVariable2 (
+             VariableName,
+             &gEfiCallerIdGuid,
+             (VOID *)&Data,
+             NULL
+             );
+  if (!EFI_ERROR (Status)) {
+    FreePool (Data);
+    gRT->SetVariable (VariableName, &gEfiCallerIdGuid, VARIABLE_ATTRIBUTE_NV_BS, 0, NULL);
+  }
+
+
+  return gRT->SetVariable (VariableName, &gEfiCallerIdGuid, VARIABLE_ATTRIBUTE_NV_BS, VarSize, (VOID *)VarData);
+}
+
+/**
+  Read etag from UEFI variable if it exists.
+
+  @param[in]    ETagList      The list to be loaded.
+  @param[in]    VariableName  The UEFI variable name.
+
+  @retval EFI_SUCCESS             All etag is read successfully.
+  @retval EFI_INVALID_PARAMETER   VariableName or ETagList is NULL.
+  @retval EFI_NOT_FOUND           No etag is found on UEFI variable.
+
+**/
+EFI_STATUS
+InitialETagList (
+  IN  REDFISH_ETAG_LIST   *ETagList,
+  IN  EFI_STRING          VariableName
+  )
+{
+  CHAR8     *VarData;
+  CHAR8     *UriPointer;
+  CHAR8     *ETagPointer;
+  CHAR8     *Seeker;
+  UINTN      VariableSize;
+  EFI_STATUS Status;
+
+  if (ETagList == NULL || IS_EMPTY_STRING (VariableName)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  //
+  // Check if variable exists already.
+  //
+  Status = GetVariable2 (
+             VariableName,
+             &gEfiCallerIdGuid,
+             (VOID *)&VarData,
+             &VariableSize
+             );
+  if (EFI_ERROR (Status)) {
+    return EFI_NOT_FOUND;
+  }
+
+  Seeker = VarData;
+  UriPointer = VarData;
+  ETagPointer = VarData;
+  while (*Seeker != '\0') {
+
+    //
+    // Find URI
+    //
+    Seeker = AsciiStrStr (UriPointer, "|");
+    if (Seeker == NULL) {
+      DEBUG ((DEBUG_ERROR, "%a, data corrupted\n", __FUNCTION__));
+      Status = EFI_DEVICE_ERROR;
+      goto ON_ERROR;
+    }
+
+    *Seeker = '\0';
+    ETagPointer = ++Seeker;
+
+    //
+    // Find ETAG
+    //
+    Seeker = AsciiStrStr (ETagPointer, "\n");
+    if (Seeker == NULL) {
+      DEBUG ((DEBUG_ERROR, "%a, data corrupted\n", __FUNCTION__));
+      Status = EFI_DEVICE_ERROR;
+      goto ON_ERROR;
+    }
+
+    *Seeker = '\0';
+
+    AddETagRecord (ETagList, UriPointer, ETagPointer);
+
+    UriPointer = ++Seeker;
+  }
+
+#if ETAG_DEBUG_ENABLED
+  DumpETagList (ETagList, L"Initial ETag List from Variable");
+#endif
+
+  Status = EFI_SUCCESS;
+
+ON_ERROR:
+
+  FreePool (VarData);
+
+  return Status;
+}
+
+/**
+  Get ETag string by given URI
+
+  @param[in]   This                    Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+  @param[in]   Uri                     Target URI to search.
+  @param[out]  ETag                    The ETag string to corresponding URI.
+
+  @retval EFI_SUCCESS                  The ETag is found successfully.
+  @retval EFI_INVALID_PARAMETER        Invalid parameter is given.
+
+**/
+EFI_STATUS
+RedfishETagGet (
+  IN  EDKII_REDFISH_ETAG_PROTOCOL *This,
+  IN  CHAR8                     *Uri,
+  OUT CHAR8                     **ETag
+  )
+{
+  REDFISH_ETAG_RECORD       *Target;
+  REDFISH_ETAG_PRIVATE_DATA *Private;
+
+  if (This == NULL || IS_EMPTY_STRING (Uri) || ETag == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Private = REDFISH_ETAG_PRIVATE_FROM_THIS (This);
+
+  *ETag = NULL;
+
+  Target = FindETagRecord (&Private->ETagList.Listheader, Uri);
+  if (Target == NULL) {
+    return EFI_NOT_FOUND;
+  }
+
+  *ETag = AllocateCopyPool (AsciiStrSize (Target->ETag), Target->ETag);
+
+  return EFI_SUCCESS;
+}
+
+
+/**
+  Keep ETag string which maps to given Uri.
+
+  @param[in]   This                Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+  @param[in]   Uri                 The target Uri which related to ETag.
+  @param[in]   ETag                The ETag to add. If ETag is NULL, the record of correspoonding URI will be removed.
+
+  @retval EFI_SUCCESS              This handler has been stoped successfully.
+  @retval Others                   Some error happened.
+
+**/
+EFI_STATUS
+RedfishETagSet (
+  IN  EDKII_REDFISH_ETAG_PROTOCOL  *This,
+  IN  CHAR8                        *Uri,
+  IN  CHAR8                        *ETag  OPTIONAL
+  )
+{
+  REDFISH_ETAG_RECORD       *Target;
+  REDFISH_ETAG_PRIVATE_DATA *Private;
+  EFI_STATUS                Status;
+
+  if (This == NULL || IS_EMPTY_STRING (Uri)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Private = REDFISH_ETAG_PRIVATE_FROM_THIS (This);
+
+  Status = EFI_NOT_FOUND;
+  Target = FindETagRecord (&Private->ETagList.Listheader, Uri);
+  if (Target != NULL) {
+    //
+    // Remove old one and create new one.
+    //
+    Status = DeleteETagRecord (&Private->ETagList, Target);
+  }
+
+  //
+  // When ETag is NULL, it means that we want to remov this record.
+  //
+  if (ETag == NULL) {
+    return Status;
+  }
+
+  return AddETagRecord (&Private->ETagList, Uri, ETag);
+}
+
+/**
+  Refresh the ETag database and save database to variable.
+
+  @param[in]   This                Pointer to EDKII_REDFISH_ETAG_PROTOCOL instance.
+
+  @retval EFI_SUCCESS              This handler has been stoped successfully.
+  @retval Others                   Some error happened.
+
+**/
+EFI_STATUS
+RedfishETagFlush (
+  IN  EDKII_REDFISH_ETAG_PROTOCOL    *This
+  )
+{
+  REDFISH_ETAG_PRIVATE_DATA *Private;
+  EFI_STATUS                Status;
+
+  if (This == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Private = REDFISH_ETAG_PRIVATE_FROM_THIS (This);
+
+  Status = SaveETagList (&Private->ETagList, Private->VariableName);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "%a, save ETag list to variable: %s failed: %r\n", __FUNCTION__, Private->VariableName, Status));
+  }
+
+  return Status;
+}
+
+/**
+  Callback function executed when the ExitBootService event group is signaled.
+
+  @param[in]   Event    Event whose notification function is being invoked.
+  @param[out]  Context  Pointer to the Context buffer
+
+**/
+VOID
+EFIAPI
+RedfishETagOnExitBootService (
+  IN  EFI_EVENT  Event,
+  OUT VOID       *Context
+  )
+{
+  //
+  // Memory is about to be released. Keep list into variable.
+  //
+  RedfishETagFlush (&mRedfishETagPrivate->Protocol);
+}
+
+/**
+  Unloads an image.
+
+  @param[in]  ImageHandle           Handle that identifies the image to be unloaded.
+
+  @retval EFI_SUCCESS           The image has been unloaded.
+  @retval EFI_INVALID_PARAMETER ImageHandle is not a valid image handle.
+
+**/
+EFI_STATUS
+EFIAPI
+RedfishETagDriverUnload (
+  IN EFI_HANDLE  ImageHandle
+  )
+{
+  EFI_STATUS  Status;
+
+  if (mRedfishETagPrivate != NULL) {
+
+    Status = gBS->UninstallProtocolInterface (
+                    mRedfishETagPrivate->ImageHandle,
+                    &gEdkIIRedfishETagProtocolGuid,
+                    (VOID*)&mRedfishETagPrivate->Protocol
+                    );
+    if (EFI_ERROR (Status)) {
+      DEBUG ((DEBUG_ERROR, "%a, can not uninstall gEdkIIRedfishETagProtocolGuid: %r\n", __FUNCTION__, Status));
+      ASSERT (FALSE);
+    }
+
+    ReleaseETagList (&mRedfishETagPrivate->ETagList);
+
+    if (mRedfishETagPrivate->VariableName != NULL) {
+      FreePool (mRedfishETagPrivate->VariableName);
+    }
+
+    if (mRedfishETagPrivate->Event != NULL) {
+      gBS->CloseEvent (mRedfishETagPrivate->Event);
+    }
+
+    FreePool (mRedfishETagPrivate);
+    mRedfishETagPrivate = NULL;
+  }
+
+
+  return EFI_SUCCESS;
+}
+
+//
+// EDKII_REDFISH_ETAG_PROTOCOL.
+//
+EDKII_REDFISH_ETAG_PROTOCOL mRedfishETagProtocol = {
+  RedfishETagGet,
+  RedfishETagSet,
+  RedfishETagFlush
+};
+
+/**
+  This is the declaration of an EFI image entry point. This entry point is
+  the same for UEFI Applications, UEFI OS Loaders, and UEFI Drivers including
+  both device drivers and bus drivers.
+
+  @param[in]  ImageHandle       The firmware allocated handle for the UEFI image.
+  @param[in]  SystemTable       A pointer to the EFI System Table.
+
+  @retval EFI_SUCCESS           The operation completed successfully.
+  @retval Others                An unexpected error occurred.
+**/
+EFI_STATUS
+EFIAPI
+RedfishETagDriverEntryPoint (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  EFI_STATUS    Status;
+
+  mRedfishETagPrivate = AllocateZeroPool (sizeof (REDFISH_ETAG_PRIVATE_DATA));
+  if (mRedfishETagPrivate == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  InitializeListHead (&mRedfishETagPrivate->ETagList.Listheader);
+  mRedfishETagPrivate->VariableName = AllocateCopyPool (StrSize (ETAG_VARIABLE_NAME), ETAG_VARIABLE_NAME);
+  if (mRedfishETagPrivate->VariableName == NULL) {
+    goto ON_ERROR;
+  }
+
+  mRedfishETagPrivate->ImageHandle = ImageHandle;
+  CopyMem (&mRedfishETagPrivate->Protocol, &mRedfishETagProtocol, sizeof (EDKII_REDFISH_ETAG_PROTOCOL));
+
+  Status = gBS->InstallProtocolInterface (
+                  &ImageHandle,
+                  &gEdkIIRedfishETagProtocolGuid,
+                  EFI_NATIVE_INTERFACE,
+                  (VOID*)&mRedfishETagPrivate->Protocol
+                  );
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "%a, can not install gEdkIIRedfishETagProtocolGuid: %r\n", __FUNCTION__, Status));
+    ASSERT (FALSE);
+    goto ON_ERROR;
+  }
+
+  //
+  // Create Exit Boot Service event.
+  //
+  Status = gBS->CreateEventEx (
+                  EVT_NOTIFY_SIGNAL,
+                  TPL_CALLBACK,
+                  RedfishETagOnExitBootService,
+                  NULL,
+                  &gEfiEventExitBootServicesGuid,
+                  &mRedfishETagPrivate->Event
+                  );
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "%a: Fail to register Exit Boot Service event.", __FUNCTION__));
+    goto ON_ERROR;
+  }
+
+  //
+  // Read existing record from variable.
+  //
+  Status = InitialETagList (&mRedfishETagPrivate->ETagList, mRedfishETagPrivate->VariableName);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_INFO, "%a, Initial ETag List: %r\n", __FUNCTION__, Status));
+  }
+
+  return EFI_SUCCESS;
+
+ON_ERROR:
+
+  RedfishETagDriverUnload (ImageHandle);
+
+  return Status;
+}
--
2.21.0.windows.1