[janderwald] 48850: [KS] - Simplify KsTopologyPropertyHandler by using KspReadMediaCategory helper - Return correct status code in case of an overflow

Author: janderwald
Date: Thu Sep 23 11:36:00 2010
New Revision: 48850
URL: http://svn.reactos.org/svn/reactos?rev=48850&view=rev
Log:
[KS]
- Simplify KsTopologyPropertyHandler by using KspReadMediaCategory helper
- Return correct status code in case of an overflow
Modified:
    trunk/reactos/drivers/ksfilter/ks/ksfunc.h
    trunk/reactos/drivers/ksfilter/ks/topology.c
Modified: trunk/reactos/drivers/ksfilter/ks/ksfunc.h
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/drivers/ksfilter/ks/ksfunc…
==============================================================================
--- trunk/reactos/drivers/ksfilter/ks/ksfunc.h [iso-8859-1] (original)
+++ trunk/reactos/drivers/ksfilter/ks/ksfunc.h [iso-8859-1] Thu Sep 23 11:36:00 2010
@@ -186,3 +186,9 @@
     IN PVOID Descriptors,
     IN ULONG DescriptorSize,
     OUT PKSPIN_CONNECT* Connect);
+
+NTSTATUS
+KspReadMediaCategory(
+    IN LPGUID Category,
+    PKEY_VALUE_PARTIAL_INFORMATION *OutInformation);
+
Modified: trunk/reactos/drivers/ksfilter/ks/topology.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/drivers/ksfilter/ks/topolo…
==============================================================================
--- trunk/reactos/drivers/ksfilter/ks/topology.c [iso-8859-1] (original)
+++ trunk/reactos/drivers/ksfilter/ks/topology.c [iso-8859-1] Thu Sep 23 11:36:00 2010
@@ -147,16 +147,9 @@
     IN  OUT PVOID Data,
     IN  const KSTOPOLOGY* Topology)
 {
-    UNICODE_STRING LocalMachine =
RTL_CONSTANT_STRING(L"\\Registry\\Machine\\System\\CurrentControlSet\\Control\\MediaCategories\\");
-    UNICODE_STRING Name = RTL_CONSTANT_STRING(L"Name");
-    UNICODE_STRING GuidString;
-    UNICODE_STRING KeyName;
-    OBJECT_ATTRIBUTES ObjectAttributes;
     KSP_NODE * Node;
     PIO_STACK_LOCATION IoStack;
-    ULONG Size;
     NTSTATUS Status;
-    HANDLE hKey;
     PKEY_VALUE_PARTIAL_INFORMATION KeyInfo;
     IoStack = IoGetCurrentIrpStackLocation(Irp);
@@ -191,79 +184,26 @@
                 break;
             }
-            Status =
RtlStringFromGUID(&Topology->TopologyNodesNames[Node->NodeId], &GuidString);
+            Status =
KspReadMediaCategory((LPGUID)&Topology->TopologyNodesNames[Node->NodeId],
&KeyInfo);
             if (!NT_SUCCESS(Status))
             {
                 Irp->IoStatus.Information = 0;
                 break;
             }
-            KeyName.Length = 0;
-            KeyName.MaximumLength = LocalMachine.Length + GuidString.Length +
sizeof(WCHAR);
-            KeyName.Buffer = AllocateItem(PagedPool, KeyName.MaximumLength);
-            if (!KeyName.Buffer)
-            {
-                Irp->IoStatus.Information = 0;
-                Status = STATUS_INSUFFICIENT_RESOURCES;
-                RtlFreeUnicodeString(&GuidString);
-                break;
-            }
-
-            RtlAppendUnicodeStringToString(&KeyName, &LocalMachine);
-            RtlAppendUnicodeStringToString(&KeyName, &GuidString);
-
-            RtlFreeUnicodeString(&GuidString);
-
-            InitializeObjectAttributes(&ObjectAttributes, &KeyName,
OBJ_CASE_INSENSITIVE, NULL, NULL);
-            Status = ZwOpenKey(&hKey, GENERIC_READ, &ObjectAttributes);
-
-            FreeItem(KeyName.Buffer);
-
-            if (!NT_SUCCESS(Status))
-            {
-                DPRINT1("ZwOpenKey() failed with status 0x%08lx\n", Status);
-                Irp->IoStatus.Information = 0;
-                break;
-            }
-
-            Status = ZwQueryValueKey(hKey, &Name, KeyValuePartialInformation, NULL,
0, &Size);
-            if (!NT_SUCCESS(Status) && Status != STATUS_BUFFER_TOO_SMALL)
-            {
-                ZwClose(hKey);
-                Irp->IoStatus.Information = 0;
-                break;
-            }
-
-            ASSERT(Size);
-            KeyInfo = (PKEY_VALUE_PARTIAL_INFORMATION) AllocateItem(NonPagedPool, Size);
-            if (!KeyInfo)
-            {
-                Status = STATUS_NO_MEMORY;
-                break;
-            }
-
-            Status = ZwQueryValueKey(hKey, &Name, KeyValuePartialInformation,
(PVOID)KeyInfo, Size, &Size);
-            if (!NT_SUCCESS(Status))
-            {
-                FreeItem(KeyInfo);
-                ZwClose(hKey);
-                Irp->IoStatus.Information = 0;
-                break;
-            }
-
-            ZwClose(hKey);
+            Irp->IoStatus.Information = KeyInfo->DataLength + sizeof(WCHAR);
+
             if (KeyInfo->DataLength + sizeof(WCHAR) >
IoStack->Parameters.DeviceIoControl.OutputBufferLength)
             {
-                Irp->IoStatus.Information = KeyInfo->DataLength + sizeof(WCHAR);
-                Status = STATUS_MORE_ENTRIES;
+                Status = STATUS_BUFFER_OVERFLOW;
                 FreeItem(KeyInfo);
                 break;
             }
             RtlMoveMemory(Irp->UserBuffer, &KeyInfo->Data,
KeyInfo->DataLength);
             ((LPWSTR)Irp->UserBuffer)[KeyInfo->DataLength / sizeof(WCHAR)] =
L'\0';
-             Irp->IoStatus.Information = KeyInfo->DataLength + sizeof(WCHAR);
             FreeItem(KeyInfo);
+
             break;
         default:
              Irp->IoStatus.Information = 0;