[WDF] Add Windows Driver Framework files

Takern from Microsoft GitHub repo:
d9c6040fe9

Licensed under MIT

sdk/lib/drivers/wdf/shared/support/km/fxdeviceinterfacekm.cpp

@@ -0,0 +1,236 @@
+/*++
+
+Copyright (c) Microsoft Corporation
+
+Module Name:
+
+    FxDeviceInterfaceKM.cpp
+
+Abstract:
+
+    This module implements the device interface object.
+
+Author:
+
+
+
+Environment:
+
+    Kernel mode only
+
+Revision History:
+
+--*/
+
+#include "FxSupportPch.hpp"
+
+extern "C" {
+#include "FxDeviceInterfaceKM.tmh"
+}
+
+FxDeviceInterface::FxDeviceInterface(
+    )
+/*++
+
+Routine Description:
+    Constructor for the object.  Initializes all fields
+
+Arguments:
+    None
+
+Return Value:
+    None
+
+  --*/
+{
+    RtlZeroMemory(&m_InterfaceClassGUID, sizeof(m_InterfaceClassGUID));
+
+    RtlZeroMemory(&m_SymbolicLinkName, sizeof(m_SymbolicLinkName));
+    RtlZeroMemory(&m_ReferenceString, sizeof(m_ReferenceString));
+
+    m_Entry.Next = NULL;
+
+    m_State = FALSE;
+}
+
+FxDeviceInterface::~FxDeviceInterface()
+/*++
+
+Routine Description:
+    Destructor for FxDeviceInterface.  Cleans up any allocations previously
+    allocated.
+
+Arguments:
+    None
+
+Return Value:
+    None
+
+  --*/
+{
+    // the device interface should be off now
+    ASSERT(m_State == FALSE);
+
+    // should no longer be in any list
+    ASSERT(m_Entry.Next == NULL);
+
+    if (m_ReferenceString.Buffer != NULL) {
+        FxPoolFree(m_ReferenceString.Buffer);
+        RtlZeroMemory(&m_ReferenceString, sizeof(m_ReferenceString));
+    }
+
+    if (m_SymbolicLinkName.Buffer != NULL) {
+        RtlFreeUnicodeString(&m_SymbolicLinkName);
+    }
+}
+
+_Must_inspect_result_
+NTSTATUS
+FxDeviceInterface::Initialize(
+    __in PFX_DRIVER_GLOBALS FxDriverGlobals,
+    __in CONST GUID* InterfaceGUID,
+    __in_opt PCUNICODE_STRING ReferenceString
+    )
+/*++
+
+Routine Description:
+    Initializes the object with the interface GUID and optional reference string
+
+Arguments:
+    InterfaceGUID - GUID describing the interface
+
+    ReferenceString - string used to differentiate between 2 interfaces on the
+        same PDO
+
+Return Value:
+    STATUS_SUCCESS or STATUS_INSUFFICIENT_RESOURCES
+
+  --*/
+{
+    RtlCopyMemory(&m_InterfaceClassGUID, InterfaceGUID, sizeof(GUID));
+
+    if (ReferenceString != NULL) {
+        return FxDuplicateUnicodeString(FxDriverGlobals,
+                                        ReferenceString,
+                                        &m_ReferenceString);
+    }
+    else {
+        return STATUS_SUCCESS;
+    }
+}
+
+
+VOID
+FxDeviceInterface::SetState(
+    __in BOOLEAN State
+    )
+/*++
+
+Routine Description:
+    Sets the state of the device interface
+
+Arguments:
+    State - the state to set
+
+
+Return Value:
+    None.
+
+  --*/
+{
+    m_State = State;
+
+    //
+    // Only set the state if the interface has been registered
+    //
+    if (m_SymbolicLinkName.Buffer != NULL) {
+        Mx::MxSetDeviceInterfaceState(&m_SymbolicLinkName, m_State);
+    }
+}
+
+_Must_inspect_result_
+NTSTATUS
+FxDeviceInterface::Register(
+    __in PDEVICE_OBJECT Pdo
+    )
+/*++
+
+Routine Description:
+    Registers the device interface for a given PDO
+
+Arguments:
+    Pdo - PDO for the device stack
+
+
+Return Value:
+    returned by IoRegisterDeviceInterface
+
+  --*/
+{
+    PUNICODE_STRING pString;
+
+    if (m_ReferenceString.Length > 0) {
+        pString = &m_ReferenceString;
+    }
+    else {
+        pString = NULL;
+    }
+
+    return Mx::MxRegisterDeviceInterface(
+        Pdo, &m_InterfaceClassGUID, pString, &m_SymbolicLinkName);
+}
+
+_Must_inspect_result_
+NTSTATUS
+FxDeviceInterface::Register(
+    _In_ FxDevice* Device
+    )
+{
+    NTSTATUS status;
+    MdDeviceObject pdo;
+
+    pdo = Device->GetSafePhysicalDevice();
+
+    if (pdo != NULL) {
+        status = Register(pdo);
+    }
+    else {
+        //
+        // Leave the device interface unregistered.  When we are in hardware
+        // available, we will register there once we know for sure we have a
+        // real live PDO that the system has acknowledged.
+        //
+        DO_NOTHING();
+
+        status = STATUS_SUCCESS;
+    }
+
+    return status;
+}
+
+NTSTATUS
+FxDeviceInterface::GetSymbolicLinkName(
+    _In_ FxString* LinkString
+    )
+{
+    NTSTATUS status;
+
+    if (m_SymbolicLinkName.Buffer == NULL) {
+        //
+        // The device interface has not yet been registered b/c it
+        // belongs to a PDO and the PDO has not been recognized by
+        // pnp yet.
+        //
+        status = STATUS_INVALID_DEVICE_STATE;
+        UNREFERENCED_PARAMETER(LinkString);
+    }
+    else {
+        //
+        // Attempt a copy
+        //
+        status = LinkString->Assign(&m_SymbolicLinkName);
+    }
+
+    return status;
+}
+