Add the EDKII_VARIABLE_LOCK_PROTOCOL implementation in SecurityPkg variable drivers.

[mirror_edk2.git] / SecurityPkg / VariableAuthenticated / RuntimeDxe / Variable.c

diff --git a/SecurityPkg/VariableAuthenticated/RuntimeDxe/Variable.c b/SecurityPkg/VariableAuthenticated/RuntimeDxe/Variable.c
index f10d8f7d8358a6344033e8ddfe256a63ded017c6..576623e88bea49d046eab7650cbce4cf88e78078 100644 (file)
--- a/SecurityPkg/VariableAuthenticated/RuntimeDxe/Variable.c
+++ b/SecurityPkg/VariableAuthenticated/RuntimeDxe/Variable.c
@@ -35,12 +35,28 @@ VARIABLE_MODULE_GLOBAL  *mVariableModuleGlobal;
 ///\r
 /// Define a memory cache that improves the search performance for a variable.\r
 ///\r
-VARIABLE_STORE_HEADER  *mNvVariableCache = NULL;\r
+VARIABLE_STORE_HEADER  *mNvVariableCache      = NULL;\r
 \r
 ///\r
 /// The memory entry used for variable statistics data.\r
 ///\r
-VARIABLE_INFO_ENTRY    *gVariableInfo    = NULL;\r
+VARIABLE_INFO_ENTRY    *gVariableInfo         = NULL;\r
+\r
+///\r
+/// The list to store the variables which cannot be set after the EFI_END_OF_DXE_EVENT_GROUP_GUID\r
+/// or EVT_GROUP_READY_TO_BOOT event.\r
+///\r
+LIST_ENTRY             mLockedVariableList    = INITIALIZE_LIST_HEAD_VARIABLE (mLockedVariableList);\r
+\r
+///\r
+/// The flag to indicate whether the platform has left the DXE phase of execution.\r
+///\r
+BOOLEAN                mEndOfDxe              = FALSE;\r
+\r
+///\r
+/// The flag to indicate whether the variable storage locking is enabled.\r
+///\r
+BOOLEAN                mEnableLocking         = TRUE;\r
 \r
 \r
 /**\r
@@ -2311,6 +2327,58 @@ IsHwErrRecVariable (
   return TRUE;\r
 }\r
 \r
+/**\r
+  Mark a variable that will become read-only after leaving the DXE phase of execution.\r
+\r
+  @param[in] This          The VARIABLE_LOCK_PROTOCOL instance.\r
+  @param[in] VariableName  A pointer to the variable name that will be made read-only subsequently.\r
+  @param[in] VendorGuid    A pointer to the vendor GUID that will be made read-only subsequently.\r
+\r
+  @retval EFI_SUCCESS           The variable specified by the VariableName and the VendorGuid was marked\r
+                                as pending to be read-only.\r
+  @retval EFI_INVALID_PARAMETER VariableName or VendorGuid is NULL.\r
+                                Or VariableName is an empty string.\r
+  @retval EFI_ACCESS_DENIED     EFI_END_OF_DXE_EVENT_GROUP_GUID or EFI_EVENT_GROUP_READY_TO_BOOT has\r
+                                already been signaled.\r
+  @retval EFI_OUT_OF_RESOURCES  There is not enough resource to hold the lock request.\r
+**/\r
+EFI_STATUS\r
+EFIAPI\r
+VariableLockRequestToLock (\r
+  IN CONST EDKII_VARIABLE_LOCK_PROTOCOL *This,\r
+  IN       CHAR16                       *VariableName,\r
+  IN       EFI_GUID                     *VendorGuid\r
+  )\r
+{\r
+  VARIABLE_ENTRY                  *Entry;\r
+\r
+  if (VariableName == NULL || VariableName[0] == 0 || VendorGuid == NULL) {\r
+    return EFI_INVALID_PARAMETER;\r
+  }\r
+\r
+  if (mEndOfDxe) {\r
+    return EFI_ACCESS_DENIED;\r
+  }\r
+\r
+  Entry = AllocateRuntimePool (sizeof (*Entry) + StrSize (VariableName));\r
+  if (Entry == NULL) {\r
+    return EFI_OUT_OF_RESOURCES;\r
+  }\r
+\r
+  DEBUG ((EFI_D_INFO, "[Variable] Lock: %g:%s\n", VendorGuid, VariableName));\r
+\r
+  AcquireLockOnlyAtBootTime(&mVariableModuleGlobal->VariableGlobal.VariableServicesLock);\r
+\r
+  Entry->Name = (CHAR16 *) (Entry + 1);\r
+  StrCpy   (Entry->Name, VariableName);\r
+  CopyGuid (&Entry->Guid, VendorGuid);\r
+  InsertTailList (&mLockedVariableList, &Entry->Link);\r
+\r
+  ReleaseLockOnlyAtBootTime (&mVariableModuleGlobal->VariableGlobal.VariableServicesLock);\r
+\r
+  return EFI_SUCCESS;\r
+}\r
+\r
 /**\r
   This code checks if variable should be treated as read-only variable.\r
 \r
@@ -2627,6 +2695,8 @@ VariableServiceSetVariable (
   VARIABLE_HEADER                     *NextVariable;\r
   EFI_PHYSICAL_ADDRESS                Point;\r
   UINTN                               PayloadSize;\r
+  LIST_ENTRY                          *Link;\r
+  VARIABLE_ENTRY                      *Entry;\r
 \r
   //\r
   // Check input parameters.\r
@@ -2717,16 +2787,6 @@ VariableServiceSetVariable (
     }\r
   }\r
 \r
-  if (AtRuntime ()) {\r
-    //\r
-    // HwErrRecSupport Global Variable identifies the level of hardware error record persistence\r
-    // support implemented by the platform. This variable is only modified by firmware and is read-only to the OS.\r
-    //\r
-    if (CompareGuid (VendorGuid, &gEfiGlobalVariableGuid) && (StrCmp (VariableName, L"HwErrRecSupport") == 0)) {\r
-      return EFI_WRITE_PROTECTED;\r
-    }\r
-  }\r
-\r
   AcquireLockOnlyAtBootTime(&mVariableModuleGlobal->VariableGlobal.VariableServicesLock);\r
 \r
   //\r
@@ -2745,13 +2805,31 @@ VariableServiceSetVariable (
     mVariableModuleGlobal->NonVolatileLastVariableOffset = (UINTN) NextVariable - (UINTN) Point;\r
   }\r
 \r
+  if (mEndOfDxe && mEnableLocking) {\r
+    //\r
+    // Treat the variables listed in the forbidden variable list as read-only after leaving DXE phase.\r
+    //\r
+    for ( Link = GetFirstNode (&mLockedVariableList)\r
+        ; !IsNull (&mLockedVariableList, Link)\r
+        ; Link = GetNextNode (&mLockedVariableList, Link)\r
+        ) {\r
+      Entry = BASE_CR (Link, VARIABLE_ENTRY, Link);\r
+      if (CompareGuid (&Entry->Guid, VendorGuid) && (StrCmp (Entry->Name, VariableName) == 0)) {\r
+        Status = EFI_WRITE_PROTECTED;\r
+        DEBUG ((EFI_D_INFO, "[Variable]: Changing readonly variable after leaving DXE phase - %g:%s\n", VendorGuid, VariableName));\r
+        goto Done;\r
+      }\r
+    }\r
+  }\r
+\r
   //\r
   // Check whether the input variable is already existed.\r
   //\r
   Status = FindVariable (VariableName, VendorGuid, &Variable, &mVariableModuleGlobal->VariableGlobal, TRUE);\r
   if (!EFI_ERROR (Status)) {\r
     if (((Variable.CurrPtr->Attributes & EFI_VARIABLE_RUNTIME_ACCESS) == 0) && AtRuntime ()) {\r
-      return EFI_WRITE_PROTECTED;\r
+      Status = EFI_WRITE_PROTECTED;\r
+      goto Done;\r
     }\r
   }\r
   \r
@@ -2776,6 +2854,7 @@ VariableServiceSetVariable (
     Status = ProcessVariable (VariableName, VendorGuid, Data, DataSize, &Variable, Attributes);\r
   }\r
 \r
+Done:\r
   InterlockedDecrement (&mVariableModuleGlobal->VariableGlobal.ReentrantState);\r
   ReleaseLockOnlyAtBootTime (&mVariableModuleGlobal->VariableGlobal.VariableServicesLock);\r
 \r